WO2022069908A1

WO2022069908A1 - Balanced cascade recirculating deep water culture hydroponics system

Info

Publication number: WO2022069908A1
Application number: PCT/GB2021/052561
Authority: WO
Inventors: Antony Philip HUTCHINSON-SMITH
Original assignee: Hutchinson Smith Antony Philip
Priority date: 2020-10-02
Filing date: 2021-10-04
Publication date: 2022-04-07
Also published as: GB2613069A; GB202015643D0; GB202205027D0; GB202201061D0; GB202214467D0; GB202114201D0; GB2599503A

Abstract

The present application relates to a Balanced Cascade recirculating deep water culture hydroponic system, or abbreviation (BCRDWC) suitable for use in hydroculture horticultural cultivation of large root fast-growing, flowering and fruiting annual plant species. The present invention provides one or more root zone containers that are served nutrient solution from a head sump unit. The system is designed such that all plants in the system may be provided nutrient solution at a balanced rate despite any difference in distance from the head sump unit.

Description

Balanced Cascade recirculating Deep Water Culture

Hydroponics System

The present invention relates to an improved hydroponics systems and method of use for the hydroponic cultivation of plants, such as annual plants for example tomatoes. Such systems provide environmentally improved horticulture, having low environmental impact, such as avoiding soil erosion, reduced use of water and land space.

Background

Traditionally plants grow in soil compost or mixtures of compost peat and soil, where nutrient Mineral elements, water, oxygen, and other microbial flora exist to feed photosynthesis and plant growth. The traditional way of plant cultivation is the natural way of plant life, as the plant searches for nutrients by root development and extension in search of water and nutrients embedded in the soil compost mix. By using this method, the elements and water are slowly leached by the root zone as the plant searches for ever-increasing bio elements for life health and reproduction. At all times to sustain healthy plant life, water has to be present for the plant to receive the nutrients for optimal, health, and flower fruit formation.

As the plants grow, they require more nutrients on an ever-increasing scale, due to this the plants have to increase root development and mass to supply the nutrients the plant needs for healthy growth and development of fruit or flower.

The natural method of plant life can have a negative effect on the plants metabolic rate as the plants have to work harder at increasing root mass in search of water and nutrients embedded in the soil. This method of plant growth expends energy that can be used in the development of a more substantial upper green foliage and the more vigorous development of fruit and flower, which in horticultural terms is where the energy needs to be, increasing the speed of crop fruit or flower output and overall Production quality.

Plants have adapted and evolved to this method of growing over many aeons of evolution, as this is the natural order of plant Biosynthesis. Plant-life has become very successful in this method of bio growth; However, we can now improve biosynthesis by giving plants precisely what they require directly to the root zone in a controlled and balanced methodology. Thus, naturally improving the plant metabolic rate by using bio nutrient preparations that directly target the requirements of the plants throughout the stages of growth, without modification of the plant genome.

Also, by controlling all aspect of root-zone uptake of the crucial nutrients and bio-stimulants in a precise feeding regime, the plants receive precisely the nutrients they require without stress and energy wastage upon the plants use whilst searching for the elements as are necessary for successful Plant metabolic function and life Cycle. Therefore, enhancing the natural metabolic rate giving rise to higher growth speed, quality & quantity of flower & fruit formation.

We as a society are now at a pivotal point in plant life nutrient technology where we can intervene in the natural growing and bioprocess of plant life, utilising the new nutrient technologies giving plants a near-perfect root environment for plant crop production, where we can feed plants with all nutrient elements they require in a highly scientific balanced and controlled method, throughout the plant's life cycle, which differs significantly at vital stages of plant growth. As long as we have the systems to deliver the balanced, controlled nutrient solutions, we can increase fruit flower quality and maximize yield outputs. These systems must be able to operate in giving high control and balanced functions with minimal maintenance by horticultural growers.

Hydroponic growing is where the root zone of a plant is given a controlled amount of nutrients in a dissolved oxygen-enriched water solution. Various and very different hydroponics methodologies have been developed throughout history, though in modern times, William Frederick Gericke first brought water culture to the forefront for scientific and public scrutiny in 1940, much to the amazement of his colleagues Gericke had some marginal success. However, the technology of the time was not yet advanced enough to make hydroponics an economic system for food production at this time in our technological evolution. Although Hydroponic growing has been around for many years, real development did not start getting recognition again until NASA began looking into the development of hydroponic systems for use in future long space exploration. Since that time, strides have been made by the horticultural society, in developing cost-effective methods of food production using hydroponics as the root zone feeding structure.

The main problem with the majority of hydroponic systems that have been developed over the years, is that they can only grow small root plants with a degree of unilateral uniform success, as the root zone environments can only sustain small plant root growth. The need to grow and develop larger plant species in a controlled nutrient and oxygen-enriched solution, has now become apparent as more diverse horticulture feed development progresses for the cultivation of high-value large plant species.

Though there have been many various & differing hydroponics systems, some known as drip feed, where the nutrient solution is drip-fed through a small diameter tube, to the root point of the plant location, where the plants are set in an inert growing material such as a rock wool medium. The drip method of growing over many years has shown great success, though has inherent problems such as clogging of the small diameter feed tubes by salt minerals contained in the nutrient solution, which is an unavoidable side effect of the nutrient solutions used in hydroponic growing. Another major flaw with this type of system, is that it is very difficult if not near impossible with any degree of success to utilise the benefits of what is known as good bacteria, or mycorrhizal inoculants which has been found to be of great benefit to the plants grown in hydroponic grow systems. This bacterium works in a symbiotic relationship with the plant, where it prevents root infection by Pythium, a form of root rot that damages the root zone causing death to the plant in many cases. Mycorrhizal Bacteria also colonises the root zone, where mycorrhizae's nodules are formed within the root structure, where the beneficial bacteria thrive due to the provision of organic nutrients in root exudate's, the Mycorrhizal bacteria in return aid the plant with nutrient acquisition, enhancing plant health and growth. All types of hydroponic system that utilise a small aperture for nutrient solution delivery, will suffer from clogging due to the proliferation and colonisation of the Mycorrhizal Bacteria added to the solution. This problem also includes any type of spray head hydroponic system, or aeroponics where the root zone is sprayed by a solution using a spray head with many small apertures.

Another hydroponics methodology is a system of growing called deep water culture. This type of design developed at first for producing a single plant in a container filled with a nutrient solution, where the plants are grown in an inert growing medium and a net pot. This design allows the roots to grow through the growing medium and the net pot into the nutrient solution, wherein air is injected by the use of an air pump and air stones. This type of single container is challenging to maintain and keep the nutrient solution in its most beneficial state for plant growth to be maximised. This type of system is only a single deep-water system, and there is no recirculation of nutrient solution. The only way to test the systems nutrient solution balance is by lifting the whole plant and root zone out of the nutrient solution, then testing the fluid for ph levels and total dissolved solids. In performing this operation, which must be done regularly, or the tester runs the risk of root zone damage and light stress as light hits the root of the plant, which must be kept in darkness at all possible times to avoid stress-related problems. Another problem with this single container deep water culture system is when the need to change out and renew the nutrient solution arises; the plant and roots must be removed from the container to carry out this action, thus causing stress on the plant, creating a negative impact on overall plant health and final yield capabilities, as each stress point damages overall productivity. This type of system is very timeconsuming on productivity, as with ten containers (as an example) in a growing area, each of these containers has to be individually checked & the solution changed on an individual basis. Though this system does function and can produce a fully-grown plant; the yield will not be optimal, Plus the time it takes to maintain more than one container is suboptimal for commercial use.

Another deep-water culture system in use, known as the undercurrent system, also known as the sub-current system, has become very popular in Canada and the USA. This system uses containers connected in a parallel line direct from one container to another; a pump then pulls the nutrient solution from one end of the parallel containers creating a negative pressure drop through the system. The nutrient solution at this point is pumped into a container, connected to the opposing end of the parallel containers, the fluid pressure builds in a back pressure, flowing through each container towards the negative pressure created by the pump. This system has significant advantages over the single deepwater unit, in that the fluid has a constant flow through the system.

Though the undercurrent system is an improvement over other types of hydroponics, it still has significant flaws that can create problems throughout the growing process, especially once the plant reaches maturity. Once this happens the root zone can start to restrict the flow of nutrient solution as it passes from one container to the other, inline towards the negative pressure created by the pump. This can start to affect the plants and the system function as the fluid begins to back up throughout the system, in such a way that the first container in the line will become overfull, whilst the last container will become starved of solution and nutrients as the movement of fluid slowly stops moving. This type of system cannot have any kind of screen in front of the outlet of each container to prevent the roots of the plant, this in itself would create a restriction that increases down the line of containers, this happens because there is no way of controlling flow, there is only one input feed line that feeds all containers in sequence one to the other.

Other problems facing the undercurrent system are the control of balanced nutrient and ph values within the nutrient solution. Over time in all types of hydroponic systems, the ph & nutrient values change, hence they go out of specification required by the plants being grown. Ph and nutrient values have to be periodically adjusted by adding a ph down an acidic solution to bring the ph values down, or ph up alkaline solution to bring the ph values up.

As the controller be it manual or automatic, adds ph up or down to the control chamber of the undercurrent system, which then has to mix the up or down solution within the nutrient solution that is out of balance. The undercurrent system, because of its design, has to take the up or down adjustment solution through the containers in parallel going one at a time down the line until it reaches the negative pressure suction pump. This fluid action can create a catastrophic change in ph levels up or down within the first container in the line, especially once the root ball is formed, the nutrient solution becomes highly toxic to the plant of the first container in the parallel line of root containers, the second then getting a slightly lower dose and so on through the system, back to the control chamber where measuring of the nutrient solution is taking place by the controller, be it automatic or manual. Not only does this create a toxic imbalance in the system, as it takes so long to balance throughout system, or for the controller to get an accurate reading to be sure the system has balanced before a decision can be made, to add more solution or not to correct any imbalance, if the system is still out of balanced specification.

If time is not taken in this process and the controller assumes the system needs to adjust pH, up or down of the solution, it then adds more of either before the system has truly balanced itself, the whole nutrient solution will crash either up or down depending upon which way the nutrient solution was out of balance. A relevant problem exists where, if the system nutrient solution has been severely depleted 'crashed' and the pH resides out at pH5 which is toxic to the plants and can create a nutrient lock. In consequence the system controller has to start adding ph up alkaline to correct the imbalance. This correction of balance in itself is adding a chemical to the solution that has no added benefit to the plant. If too much ph up or down is added to the nutrient solution, the chemical will accumulate which can become poisonous to the plants causing a toxic response, damaging the plants at the point of toxicity, this overload can be undone if addressed early enough to stop the total demise of the plants. Though irreversible damage may occur, at this point the system has to be purged of nutrient solution and replaced with a new solution to be sure that the plants have the best possible nutrient levels and ph levels for maximum harvest output. This action in itself is a waste of valuable time, water and nutrient additives. This problem requires addressing.

Additional problems can arise when it comes to a complete nutrient solution change, which in most cases should frequently happen, with fortnightly changing being preferred across most hydroponic systems. Most types of hydroponic system use a gravity drain to empty the system of nutrient solution, which significantly relies on the drain outlet being at a lower level than the system outlet. In many cases, this is not practical and can create problems in the placement of the systems. If the system is lower than any drain outlet point, the system must be raised to accomplish complete drainage of the nutrient solution, or a separate pump has to be used, which is extra cost & more time involved in setting this up.

There is therefore a need to address the above problems by the provision of an improved hydroponics system.

Summary

The present invention in its various aspects is as set out in the appended claims.

The present application relates to a Balanced Cascade recirculating deep water culture hydroponic system, or abbreviation (BCRDWC) suitable for use in hydroculture horticultural cultivation of large root fast-growing, flowering and fruiting annual plant species. The BCRDWC system, designed to balance and increase nutrient and oxygen uptake, by recirculating a nutrient oxygen-rich solution, around the root zone of a plant, where the (BCRDWC) system maintains ph and nutrient balance. By using a balanced and controlled regulation of nutrients, oxygen and temperature around the plant root zone, all growth and flower formation is increased by the controlled balanced application of precise nutrient-based science; therefore, this combination of root zone control will give a consistently high quality and quantity flowering fruit yield. The Balanced Cascade Recirculating Deepwater Culture System is specifically designed to alleviate and solve problems inherent to deepwater culture hydroponics and other types of hydroponics.

A deep water culture hydroponic system is a term of art and refers to the hydroponic method of plant production by means of suspending the plant roots in a solution of nutrient-rich, oxygenated water.

The present invention provides a deep-water hydroponics system, the system comprising:

One or more root zone containers; Each root zone container comprising: a root zone Nutrient inlet, a root zone Nutrient return and a growing medium. The root zone nutrient inlet and the root zone nutrient return may be apertures in a wall of the root zone container. The growing medium is configured for growing a plant or plants therein acting as an anchor point for the roots to grow through down into the nutrient solution.

The root zone containers may have a depth measured from a base of the container to an open end of the container through which a plant may grow. The depth of the root zone containers may preferably be between 10 and 100cm, further preferably between 25 and 40 cm. The exact sizing of the root zone containers may depend on the plant to be grown in said container, as an example, plant of around 120cm to 150cm in height will grow best with a root zone depth of minimum of 31cm with a diameter of 31cm.

The growing medium may also have a height, the height of the growing medium preferably being less than the depth of the root zone container, more preferably the height of the growing medium is between a third of and half the height of the root zone container. The growing medium may be positioned within the root zone container such that there is space between the bottom of the growing medium and the bottom of the root zone container. The height of the growing medium may preferably be between 10 and 50cm, further preferably between 13 and 20 cm. The diameter of the growing medium may preferably be between 10 and 20 cm, further preferably between 13 and 15cm. This has been found to give stability to young plants whilst providing enough space in the root zone container below the pot for the roots to grow into.

The open end of the root zone container may comprise a lip, the lip extending from the edge of the container and into the open end of the container. The growing medium may be further be configured with a lip at the tip of the growing medium that extends out away from the growing medium such that the lip of the growing medium sets onto the top of the root zone container to keep the growing medium in place and flush with the top of the root zone container.

The system further comprises a head sump unit; the head sump unit comprising: a head sump container configured to hold liquid; a pump; a head sump nutrient outlet; at least one head sump nutrient return. The at least one head sump nutrient inlet and the at least one head sump nutrient return may be apertures in a wall of the head sump container. The liquid held by the container may preferably be a nutrient solution designed for optimal growing conditions of the plants to be grown in the root zone containers. The head sump container preferably has a base and one or more sides. The head sump container may have a circular base and cross sectional area along the height of the container parallel to the base. This provides uniform nutrient circulation and easier cleaning.

The system further comprises at least one primary nutrient outlet line, also termed the primary nutrient outlet feed line; wherein a first end of the at least one primary nutrient outlet feed line is attached to the head sump nutrient outlet and a second end of the at least one primary nutrient outlet line is attached to the valved root zone nutrient inlet of a first root zone container of the one or more nutrient containers such that there is fluid communication between the valved root zone nutrient inlet of the first root zone container and the head sump nutrient outlet. The attachment between the line and the root zone container and head sump unit are preferably made using a watertight seal.

The primary nutrient outlet line may split into more than one primary nutrient outlet lines after leaving the head sump unit, this may allow for more root zone containers to be added, allowing the BCRDWC hydroponic system to increased output capacity to be arranged closer to the head sump unit making the system as a whole more compact.

The system further comprises at least one primary nutrient return line; wherein a first end of the at least one primary nutrient return line is attached to the root zone nutrient return of the first root zone container and a second end of the at least one primary nutrient outlet line is attached to the at least one head sump nutrient return such that there is fluid communication between the root zone nutrient return of the first root zone container and the at least one head sump nutrient return, size & shape dependent upon system requirements.

The lines of the present invent on are preferably pipes, further preferably pipes with a circular cross section.

The lines are preferably made of a plastic, to reduce weight and corrosion.

All connections between the containers and lines of the present invention are preferably made with a watertight seal such that there is no nutrient solution loss through leaking.

The submersible pump is connected to the head sump valved nutrient outlet and configured to pump liquid from the head sump container through the primary nutrient outlet line and into the one or more root zone containers, this ensures that the nutrient solution arrives at the one or more root zone containers at a positive pressure.

The present invention provides the benefit that a nutrient solution from the head sump unit can be circulated through the one or more root zone containers cascading over the root zone as it does so.

To accommodate more than one root zone container in the system, the primary nutrient outlet feed line may comprise one or more valved inlet spurs, each of the one or more inlet spurs providing fluid communication between the primary nutrient outlet feed line and a root zone nutrient valved inlet of one of the one or more root zone containers. Similarly, to provide return of nutrient solution from the additional root zone containers, the primary nutrient return line comprises one or more return spurs, each of the one or more return spurs providing fluid communication between the primary nutrient return line and a root zone nutrient outlet of one of the one or more root zone containers. The inlet spurs may each comprise a T-section of pipe. This allows the primary nutrient outlet line to continue along the straight section of the T-section and the spur to begin from the part of the T- section that is perpendicular to the primary nutrient outlet. The T-section may be a reducing tee off pipe section The reducing tee off pipe section serves to reduce the cross-sectional area spur relative to the cross-sectional area of the primary nutrient outlet line. The primary nutrient outlet line preferably has a larger cross-sectional area than the spur as the primary nutrient outlet line will, if the system has more than a single root zone container, need to have a higher capacity per unit time than the spur in order to feed all of the plants in the system at the same rate.

The ratio of cross-sectional areas between the primary nutrient outlet and the spur(s) may be between 5:1 and 3:2. More preferably, the ratio of cross-sectional areas between the primary nutrient outlet line and the spur(s) may be 2:1 this has provides an optimal compromise between system pressure required for nutrient provision and flow rate of the provision, particularly when supplying more than 10 root zone containers.

Note than the root zone container that is furthest from the head sump unit along the primary nutrient outlet line is where the primary nutrient outlet line terminates, in this case, the spur may be bend, preferably a 90-degree bend, in the primary nutrient outlet line that directs the primary nutrient outlet line into the root zone nutrient inlet of the furthest root zone container. Lint all other root zone nutrient inlets in the system, the root zone nutrient inlet of the furthest root zone container will be valved.

The one or more primary nutrient return lines may preferably have a cross sectional area larger than that of the primary nutrient outlet line. This takes into account that the primary nutrient outlet line is pressurised by the pump, the return line on the other hand, is not pressurised to the same extent. Preferably, the one or more primary nutrient return lines have a cross sectional area that is between 1.5 and 3 times as large as the primary nutrient outlet. Most preferably, the primary nutrient return lines have twice the cross-sectional area of the primary nutrient outlet line. This has provided an optimal compromise between system pressure required for nutrient provision and flow rate of the provision, particularly when supplying more than 10 root zone containers.

The primary nutrient outlet line may split into two or more arms of the primary nutrient outlet, each of the two or more serving a run of root zone containers. Each run of root zone container may comprise any number of root zone containers distributed along the arms of the primary nutrient outlet line. The spurs may extend from the arms of the primary nutrient outlet.

The cross-sectional area of the lines and spurs of the system are preferably circular, however other cross-sectional areas may be considered.

The head sump nutrient outlet may comprise a nutrient outlet directional valve, the nutrient outlet directional valve configured to control the direction of liquid flow through the head sump nutrient feed outlet from the head sump unit into the primary nutrient outlet feed line.

The pump may be a bottom suction submersible pump (BSSP). This provides the benefits of allowing the pump to completely drain the system, if necessary, preventing nutrients settling in the head sump unit and allows easy removal of the pump for system cleaning. The pump may preferably be placed at a centrally located point at the lowest position of the head sump unit. This position allows all recirculated nutrient solution to be collected by the BSSP, then re-mixed before returning through the system in a continuous recirculating motion.

The pump may be configured to circulate the liquid in the system at a rate of between 10 and 30 circulations per hour. Further, it may be preferable that the pump is configured to circulate the liquid in the system at a minimum rate of 20 complete circulations per hour as this has been found in testing to deliver optimum growing conditions.

The head sump unit may further comprise a waste outlet. The waste outlet may preferably be an aperture connected to a waste pipe on to outside of the head sump unit.

A pipe may extend from the pump then split into an outlet feed arm and an outlet waste arm, the outlet feed arm connected to the head sump nutrient feed outlet and the outlet waste arm connected to the waste outlet. The outlet arm may comprise an outlet feed valve and the waste arm may comprise an outlet waste valve. This allows the pump to be used to either circulate liquid around the system with the outlet waste valve closed and the outlet feed valve open. Then, when the system is to be emptied, the outlet feed valve can be shut off and the outlet waste valve opened to allow the pump to empty the system. The pipe may be connected to the BSSP between the pipe and the BSSP may be made by a rubberised pipe section that acts as a vibration dampener. The rubberised pipe section may then connect to a solid high rigidity material split pipe section, that becomes the feed outlet arm and outlet waste arm.

Where the waste valve is placed in the open position and the outlet feed valve open, the system will start to empty at a slow rate as the system continues to recirculate the nutrient fluid, disturbing any built-up bio elements as the fluid level slowly reduces through the root zone of the plant, carrying out all bio-waste in the waste nutrient solution as it passes through the nutrient return lines.

A root zone valve is be connected to the root zone nutrient inlet of each of the one or more root zone containers such that liquid passes through the valve before entering the root zone container, this allows the rate of liquid flow into the root zone containers to be controlled on an individual basis. The valve may be positioned on a spur. Having a valve controlling the rate of liquid flow into each root zone containers allows the system to remain balanced in the case of multiple root zone containers, without the valves, as the pump pressurises the system, more liquid would flow into the root zone containers closest to the pump than into those furthest from the pump. Essentially over feeding the plants closest to the pump and underfeeding those farthest from the pump. The valves allow the amount of liquid flow into the root zone containers to be controlled to the point that all the plants are being fed at the same rate throughout the system giving a uniform growth rate along the plants in the system. By cascading the nutrient solution into the root zone containers at a balanced & measured rate, the level of the nutrient solution rises in each root zone container at an even and balanced level until there is enough gravitational force generated to push the nutrient fluid out through the root zone nutrient return.

By the controlled balanced cascade of the nutrient solution onto the top of the root zone in a fully valved function, the nutrient solution surrounding the root ball is agitated in such a way to prevent high salt concentrations collecting at points around the root zone ball, which can become toxic if left unchecked for any length of time. This toxic salt concentration and build-up can lead to a negative impact upon growth, plant health & wellbeing, or can cause plant necrosis & death if not corrected or prevented. Also, by cascading the nutrient solution into the root zone container and onto the top of the roots, the flow of the cascading solution breaks surface tension carrying with it extra oxygen, which circulates the root zone, along with the oxygen from the bubblers placed at the bottom of each root zone container., The Ph and Tds (Total dissolved solids) of the nutrient solution can go out of specified balance and periodically has to be brought back into a specific range for the type of plants being grown, this is a particular problem in undercurrent systems. The BCRDWC system does not suffer from the described problems due to the root zone containers being fed individually along the main feed line at the same rate as each other root zone, this does not rely upon pass through, from one container to the next along the line. This process of nutrient feed balance benefits the plants as all root zones can be adjust in values at the same rate from a single point, being the head sump unit. With this balanced function and control, the system balances very quickly at an even rate of change in Ph and Tds values back to the desired levels, with the plants never experiencing a toxic crash or overload as described with other systems.

The root zone valves may be manual or automatic. In the case that the valves are automatic, the system may further comprise a controller in communication with the root zone valve.

The present invention is preferably controlled by a computer controller in the form of a computing system. This allows continuous uninterrupted system control in real time for large numbers of plants. References to control, controlling in the present application are preferably performed by such a controller.

The valves may preferably be solenoid valves. Further preferably, the valves may comprise or used in conjunction with root zone flow meters for measuring the flow rate into each of the root zone containers. The root zone flow meters may preferably be connected to the controller. The controller may then be configured to adjust the valves such that the root zone flow meters are all measuring the same flow rate.

The BCRDWC system has been designed to act as a balanced system, utilising valves of manual or automatic function at each spur point off the primary nutrient outlet line. These valves control the flow through each root zone container from the primary nutrient outlet line. By the control of each spur point by a valve system, each of root zone containers attached to the main feed line receives a balanced highly enriched nutrient solution, of the same nutrient solution proportions and properties. By controlling the nutrient feed solution in a balanced function, the system can be expanded exponentially from one root zone container onwards dependent upon requirements, size and shape of the growing environment, which do not detract from functionality as layout of the system can be modified to fit the available space with functionality remaining the same. A primary nutrient outlet line or arm of the primary nutrient outlet line runs parallel to each row of root zone containers in one continuous line until the last root zone container is reached. The outlet lines can be spaced in rows, or even placed in a circular position if so required, with root zone containers around the feed lines, this gives scope for any shape to be created, which offers the BCRDWC system limitless design shape applications without functionality alteration.

The system has the benefit, in that it can run nutrient solutions with Mycorrhizal bacteria present within the nutrient solution, as the system design does not require any small diameter pipes or spray heads that can clog requiring heavy maintenance and possible damage to the plants— thus giving rise to the symbiotic relationship between plant & bacteria, which protects the plant from rootbased pathogens & increases overall yield & Quality.

Through the use of the present invention, the plant health and growth are kept uniform in size from one plant to the other plants throughout the BCRDWC system & through the plant life cycle, this uniformity takes place because the BCRDWC enriches & mixes the deep-water nutrient solution held in each of the root zone containers at an even and sustainable rate of recirculation.

The spurs may be evenly spaced along the primary nutrient outlet line. Alternatively, the position of the spurs along the primary nutrient outlet line may be adjusted to allow for the differing area requirements of the plants being grown in the system, this spacing allows for light penetration down through the plants, giving rise to more significant photosynthetic activity, this increases overall health and productive output of the plants cultivated.

Each of the root zone containers may be configured such that the root zone nutrient inlet is above the set nutrient solution level contained within the root zone container such that liquid from the root zone nutrient inlet cascades over the roots of the plants contained within the root zone container. By the cascade of the nutrient solution onto the top of the root, the nutrient solution surrounding the root ball is agitated in such a way to prevent high salt concentrations collecting at points around the root zone ball, which can become toxic if left unchecked for any length of time. This toxic salt concentration and build-up can lead to a negative impact upon growth, plant health & wellbeing, or can cause plant necrosis & death if not corrected or prevented. Also, by cascading the nutrient solution into the root zone container and onto the top of the roots, the flow of the cascading solution breaks surface tension carrying with it extra oxygen, which circulates the root zone. The one or more root zone containers may be removable. The root zone nutrient outlets and inlets may comprise removable connection points. As such, a user may be able to close the root zone valve, wait for the system to drain, then decouple the root zone container from the system at the root zone nutrient inlets and outlets. This allows for cleaning, maintenance or replacing of individual root zone containers without shutting down the whole system.

The root zone nutrient return may be placed at the bottom opposing side to the root zone nutrient inlet. This provides the benefit of the root zone container being able to be fully trained by gravity. Once there is enough gravitational force generated by liquid in the root zone container to push the nutrient fluid out through the root zone nutrient return, the liquid enters the nutrient return line where it enters a negative pressure environment, created by the suction of pump built into the head sump container unit.

The one or more root zone containers may further comprise along with the oxygen bubblers placed at the bottom of each root zone container. As with all deep-water hydroponics, oxygen is preferably injected at each root zone for optimal function of the system, keeping the nutrient solution at maximum oxygenated levels, for plant health.

The one or more root zone containers may comprise a level indicator, the level indicator may be a transparent vertical section of the root zone container. Preferably, the level indicator is a level indicating sight glass. This advantageously giving the operator a visual indicator of possible root blockage. As the root zone valves in the system ensure that the level of liquid in the root zone containers remain approximately constant, the level indicator shows an increase in the level of liquid in a root zone container, this implies a blockage. The blockage may be caused by roots of the plant in the container growing into the root zone nutrient outlet of the root zone container and blocking liquid from exiting the root zone container. Such identification of root blockage is less time consuming that by visual inspection and is more readily automated. The pump may be further configured to draw liquid from the one or more root zone containers and back to the head sump container so as to speed up circulation of the nutrient solution. This may be achieved by the pump being a bottom suction submersible pump causing a negative pressure in the primary nutrient return line. This will assist in increasing the number of circulations of fluid per hour which in turn has benefits for plant growth.

The head sump unit may comprise a lid to reduce evaporation and contamination.

The head sump unit comprises an adjustable auto top off valve. Adjustable auto top off valve may preferably be a float valve. A user can configure the valve to a pre-set liquid level in the head sump unit. This level may preferably be the level in the head sump unit that corresponds to the level in the one or more root zone containers being between 10 and 40mm below the growing medium.

The adjustable auto top-up valve may comprise a flow meter such that the amount of liquid ingress into the head sump unit can be monitored.

The system may further comprise a top-up tank, the top up tank configured to hold liquid, preferably nutrient solution. The top up tank may be connected to the head sump unit through a top up line such that liquid from the top up tank can be introduced into the head sump unit. The top up line may be connected to the head sump unit through the adjustable auto top up valve.

If the level of liquid drops below the pre-set level, the valve may open allowing liquid from the top up tank into the head sump unit to top up the system. Once the liquid reaches the pre-set level, the adjustable auto top up valve will close leaving the liquid level in the head sump unit at the pre-set level.

Alternatively, the adjustable auto top up valve may be connected to a controller, the controller may be configured to open the valve once the liquid level in the head sump unit reaches a level a predetermined amount below the pre-set level in the head sump unit. The controller may then close the valve once the pre-set level has either been reached or exceeded by a second predetermined amount. This is beneficial because flow meters are generally less accurate at low flow rates, therefore, by ensuring that the top up will be of a larger volume of liquid due to the level in the head sump unit decreasing to the predetermined amount below the pre-set level, the valve will be open wider to allow faster flow, and more accurate nutrient ingress readings will be acquired.

Top up tank may comprise a stirrer to agitate the nutrient solution and keep it uniformly mixed.

The top up tank may comprise an air bubbler to keep the nutrient solution oxygenated before it is input into the head sump unit.

The system may further comprise a fill tank. The fill tank may be removably connected to a fill point of the system via a fill pipe. This allows the fill tank to be connected to the system when the system is to be filled or flushed, and then disconnected after fill ing/f lushing. The fill tank may comprise a pump to move liquid from the fill tank into the fill point of the system. The pump of the fill tank may preferably be a bottom suction submersible pump.

Th fill point may comprise a flow meter for determining the volume of liquid being input into the system.

The head sump unit may comprise a fill level indicator. This will allow the unit to be filled to the same level consistently after a nutrient solution change, regardless of the amount of root mass that has developed in the root zone containers in the system. As root mass develops it will displace the liquid in the root zone containers, and as a result, filling the system with the same volume of liquid each time could lead to overflow. Further this may allow for the overall volume of root below the liquid level of the root zone containers calculated, if the volume of liquid used to fill the system to a particular level at each fill and refill is known.

The adjustable auto top of valve may be configured such that when the liquid drops below a certain level in the head sump unit, the pump shuts off until the liquid rises above the level of the adjustable auto top off valve.

The growing medium may comprise a net pot. The net pot acts as a setting and root anchor point, and may be filled with an inert growing medium, as example rock wool cubes or other inert growing material. The inert growing material allows for younger plants with root systems that would not fill the net pot to be introduced into the system, providing a stable growing medium for said plants as their roots grow to fill and exit the pot. The roots of the plant grow through the inert growing material & enter the oxygen enriched nutrient solution in the bottom of the root zone container where they thrive and draw all nutrients for the upper green foliage. The net pot allows the roots to grow freely without constriction, yet provides enough structure to support the plant.

The head sump unit may comprise a heating or cooling element for heating or cooling the liquid in the system. The heating and cooling element may further comprise a thermostat such that a user can set a temperature of the liquid and the heater will maintain that temperature. The head sump unit may comprise one or more water testing sensors, the sensors may be configured to test one or more of pH levels, Nutrient levels, temperature, oxygen levels. This would allow a controller to automatically determiner what needs to be added to the nutrient solution to bring it back to the optimum balance.

The system may include one or more filters. It may be preferable that each of the root zone containers comprises one or more filters, the filters may further preferably be positioned at the root zone nutrient return so as to prevent any debris from the root ball being sucked back into the head sump unit and through the pump. The filter may preferably have apertures between 1mm and 20mm in diameter, further preferably between 7mm and 15mm so as to ensure removal of larger detritus but whilst having apertures large enough to not become clogged by mycorrhizae if mycorrhizae are used in the nutrient solution circulating around the system.

The pump capacity may be dependent upon the number of root containers attached to the head sump unit.

It is to be understood that the present invention, i.e., the joints between the head sump unit, lines and containers, are intended to be watertight to ensure no loss of water through leaking and to reduce losses through evaporation unless the system is drained purposefully. This makes the present system more efficient and better able to maintain optimum nutrient concentration.

In another aspect, the present invention may comprise a method for using the system as described above.

The method comprising, filling the system with liquid. Opening all the root zone valves to fully open, Turning on the pump.

As the pump pressurises the main nutrient feed lines the root zone valves should be placed in the fully open position on all spur lines allowing the the nutrient solution to flow into the root zone containers at an initially unbalanced rate, as the nutrient solution will always flow at a greater volume to the first spur point on the main feed line.

The method further comprises adjusting the root zone valves until the rate of liquid ingress into each of the root zone containers is the same. This may be determined by observing the liquid level in each of the root zone containers as the liquid level in the root zone containers is a result of the balance of the rate of liquid in through the root zone nutrient inlet and liquid exiting through the root zone nutrient outlet.

The method may include adjusting the valves of the root zone containers such that the liquid level is between 10 and 40mm below the bottom of the growing medium. A typical depth of liquid in a root zone container for the present invention is in the range 10 to 25cm.

The root zone valves may preferably be adjusted from the first root zone valve to the last spur point flow valve along the main nutrient feed lines. The first root zone valve being the root zone valve closest to the head sump unit along the primary nutrient outlet line. By making small incremental adjustments from the first to the last in the line thus balancing the flow volume of nutrient solution to each root zone container.

Through balancing the BCRDWC system using a valve system as described, each root zone container receives an equal amount of nutrient solution passing through the root zone of each plant along the, giving maximum nutrient oxygen & water uptake by the plants' root zone at a balanced and equal rate. This action creates a uniform growth rate of plants along the line, which is the desired outcome of all growers alike. Also, this function of control, using valves at each root zone container allows for the expandability as previously mentioned. Once the system is balanced, the method may comprise placing a plant in the growing medium of each of the root zone containers. It is preferable to place the plants in the root zone containers after balancing the system to avoid the plants being damaged by the unbalanced flow during setup.

Detailed Description

The present invention will now be described in terms of the following figures.

(Fig 1) Side elevation possible Head Sump Unit

(Fig 2) Plan of possible Head Sump Unit

(Fig 3) Plan of Possible system layout, Showing Head sump unit in connection to Root Zone containers

(Fig 4) Side elevation of possible Root zone container

(Fig 5) Plan of Possible Root zone container

(Fig 6) Plan of Possible Nutrient fluid flow

(Fig 7) Plan of possible multiple root zone system

(Fig 8) Side elevation of possible system including tanks

(Fig 9) Plan of possible system including tanks

(Fig 10) Side elevation of head sump unit and root zone container showing liquid flow and levels

(Fig 11) Plan of head sump unit and root zone container showing liquid flow and levels

Figures 1 and 2 show the head sump unit 100 from a side on and pan view respectively. The head sump unit 100 comprises a container, within the container a pump 101, in this case a bottom suction submersible pump BSSP. Wherein a pipe 102 extends from the pump then splits at a junction 103 into an outlet valved arm 105 and a waste valved arm 104, the outlet valved arm 105 is connected to the primary nutrient outlet feed arm 107, 109, 111, 112 through the head sump nutrient outlet and the waste valved arm 104 is connected to the waste outlet pipe 106 through the waste outlet in the head sump unit; wherein the outlet arm comprises an outlet valve and the waste arm comprises a waste valve. The waste arm passes through an aperture in the wall of the head sump unit, the waste outlet, and into the waste outlet pipe 106

The pipes through both the waste outlet and nutrient outlet are each connected using a watertight seal 108.

Figures 1 and 2 also show the fill point 110. The fill point may also serve as a flush point, i.e., the system may be filled with nutrient solution and run with the view to cultivate plants in the root zone containers. Alternatively, water or a cleaning solution may be introduced through the fill point 110 and the system pump run to flush out and clean the system circulating cleaning fluid back to the pump & out to waste collection.

In figure 1, the primary nutrient outlet arm comprises a T junction, 'tee', pipe section 109 with the straight section of the tee positioned up and down in relation to the head sump unit 100. The fill point 110 sits above the tee pipe section. The fill point 110 may be valved, to stop return flow or may be capped off whilst the system is in recirculation mode. Placed in the down section of the tee pipe straight is a nominal section of pipe 111 leading to a connection joint 112 at the bottom of nominal section of the pipe 111 to allow for the connection to an additional section of the primary nutrient feed outlet arm that feeds the root zone containers.

The head sump unit in figures 1 and 2 also comprises an adjustable auto top off valve 113 this may be referred to as AATOFV. The AATOFV 113 is may be placed at the opposing side to the head sump nutrient returns 204. This position prevents incorrect control values, due to possible buffeting from the returning nutrient solution upon the adjustable control float.

Figure 3 discloses the head sump unit as described in figures 1 and 2, with the addition of a section of the system including the primary nutrient outlet 201 and two primary nutrient returns 204.

The primary nutrient outlet line exits the head sump unit 100 and splits into two at a T-section of pipe. Following one of the subsequent arms of the T-section, the primary nutrient outlet line continues until it reaches a spur 304. The spur comprises a T-section of pipe 202, the T-section may be a reducing tee off pipe section (the reducing tee off pipe section may have a predetermined internal diameter of the reduction section of the said tee point, dependent upon the requirements of the user and flow required). The primary nutrient outlet line 201 extends either side of the straight section of the T section, the section of the T-section that is perpendicular to the primary nutrient outlet line 201 connects to a root zone container 306 at a root zone nutrient inlet 305. The root zone nutrient inlet is preferably formed of a watertight seal. The spur 304 comprises a root zone valve 302.

The root zone container 306 further comprises a root zone nutrient outlet 203, an air bubbler 309 and a level indicating sight glass 307.

Following the T-section 202, the primary nutrient outlet line 201 continues before reaching another spur 304, the spur 304 is configured on the same manner as described above and attached to a root zone container. As such, the system may comprise any number of spurs and root zone containers.

Both root zone containers 306 in figure 3 also comprise a root zone nutrient return 203, the root zone nutrient return 203 connects to the primary nutrient return line 204. In the system described in figure 3, there are 2 primary nutrient return lines 204, the second primary nutrient return line serves the root zone containers 306 (not pictured) that would be served by the arm of the primary nutrient outlet 201 that split to the right at the t-section of pipe following the head sump nutrient outlet.

Figures 4 and 5 show a root zone container 306 in side on cross section and top-down views respectively. Nutrient solution may enter the root zone container 306 through the root zone nutrient inlet 305. The root zone nutrient inlet is connected to a spur 304 that is fed by the primary nutrient outlet feed line. The spur begins at a T-section 202 and continues vertically upwards through a root zone valve 302 before entering the root zone container at the root zone nutrient inlet 305. In this figure it can be seen how the nutrient solution will flow from the root zone nutrient inlet, cascading over the roots of a plant that have grown through the net pot 308. The roots of the plant will then settle into the deep-water nutrient solution flowing and contained within the root zone container where they can be oxygenated by the air bubbler 310, the air bubbler 310 draws air from an air inlet 309 that is positioned in the side of the root zone container. When the plants are small/in their infancy, the roots of the plant will be contained within the net pot. At this stage, the plants will get nutrients from the cascade of nutrient solution coming from the root zone nutrient inlet 305. As the plants grow, their root system will extend down into the root zone container to feed off the nutrient solution that settles at the base of the container. The level of nutrient solution in the rootzone container may be determined by the user using the level indicating sight glass 307. The level indicating sight glass is preferably positioned to give the user a precise indication of the nutrient fluid levels within the root zone container. The nutrient levels within the root zone container may be adjusted using the adjustable auto top off valve 113.

The net pot 308 is positioned at the top of the root zone container and may be chosen to have the optimum size required for the plants being cultivated. The net pot acts as a setting and root anchor point and may be filled with an inert growing medium, as example rock wool cubes or other inert growing material. The roots of the plant grow through the inert growing material & enter the oxygen enriched nutrient solution where they thrive and draw all nutrients for the upper green foliage.

At the lowest point of the side of the root zone container 306 is the root zone nutrient return 203. The root zone nutrient return is preferably on the opposing side of the root zone container 306 to the root zone nutrient inlet 305 to allow the cascading nutrients to pass through the root zone maximizing nutrient replenishment of the root zone. In figure 3, the root zone nutrient return leads to a Tee section pipe, the straight sections of the tee section pipe forming part of the primary nutrient return line 204. The nutrient return line 204 which connects each root zone container in line back to the head sump unit 100.

It should be noted that for the root zone container furthest from the head sump unit along each arm of the primary nutrient outlet line 201, the spur 304 and the root zone nutrient return 203 will be not have a tee section of pipe, rather the primary nutrient outlet line 201 will be connected to a root zone valve and then into the root zone nutrient inlet of the furthest root zone container. The primary nutrient return line will effectively begin at the root zone nutrient outlet of the furthest root zone container. This is effectively described in figure 6. In figure 6, the primary nutrient outlet line 201 leaves the head sump unit and splits at a tee section of pipe into two primary nutrient outlet lines. Along each arm of the primary nutrient outlet lines there are 4 spurs 304, the 3 spurs closest to the head sump unit are facilitated by tee sections of pipe allowing the primary nutrient outlet line to continue. At the 4^th and final spur, the primary nutrient outlet line 201 terminates at the root zone nutrient inlet of the 4^th (furthest) root zone container. For each arm of the primary nutrient outlet feed line 201 there is a corresponding primary nutrient return line 204. The primary nutrient return lines 204 begin at the furthest (4^th in this case but any number of root zone containers is conceivable) root zone container along their respective arm of the primary nutrient outlet line 201 and continue back towards the head sump unit 100, joining with the root zone nutrient returns of the root zone containers served by respective arm of the primary nutrient outlet line 201 before connecting to the head sump unit 100.

Figure 7 illustrates an expansion of the concept shown in figure 6. In this case, the primary nutrient outlet line 201 splits into 4 so that 4 runs of root zone containers can be served in parallel. As the primary nutrient outlet feed line is split into 4, there are 4 corresponding primary nutrient return lines 204, each serving a run of root zone containers. In the figures each run of root zone containers are shown as being in straight lines, this is for clarity only and is not intended to be limiting. One of the benefits of the present invention being that the system can be adapted to fit into the space that a user has available, this may require arranging the root zone containers in concentric circles for example.

Figures 8 and 9 show top down and side elevations respectively of a system including a head sump unit 100 and a root zone container 306 connected as disclosed in figure 3. Although only 1 root zone container is shown, this system could be configured with a plurality of root zone containers arranged for example like those in figures 6 and 7. The system includes an auto refill tank 400 and a fill tank 410. The auto refill tank is connected to the head sump unit through the adjustable auto top off valve 113 via an auto refill pipe 420. The fill tank 410 is connected to the fill point 110 of the system via a fill pipe 440. The fill tank 410 comprises a pump 450 to pump liquid from the fill tank 410 through the fill point 110.

Figure 10 and 11 show close ups of figures 8 and 9 without the tanks. The function of the system is illustrated with arrows indicating the direction of liquid flow through the system. The pump 101 draws liquid in the head sump container up through the pump 101 and into the primary nutrient outlet line 201. The primary nutrient outlet line 201 carries liquid form the pump at a positive pressure into the foot zone container, the liquid cascades over into the root zone container onto the root ball, the root ball being the roots outside of the net pot. The liquid level in the root zone container is as a result of the balance between the liquid ingress rate through the root zone nutrient inlet and the liquid egress rate through the root zone nutrient outlet. The liquid returns from the root zone container via the primary nutrient return line 204 aided by gravity and negative pressure from the pump 101.

Claims

Claims A deep-water hydroponics system, the system comprising: one or more root zone containers; each root zone container comprising: a root zone Nutrient inlet; a root zone Nutrient return; a growing medium; wherein a root zone valve is connected to the root zone nutrient inlet of each of the one or more root zone containers such that liquid passes through the valve before entering the root zone container; and wherein the root zone nutrient inlet and the root zone nutrient return are apertures in a wall of the root zone container; a head sump unit; the head sump unit comprising: a head sump container configured to hold liquid; a pump; a head sump nutrient outlet; at least one head sump nutrient return; wherein the at least one head sump nutrient outlet and the at least one head sump nutrient return are apertures in a wall of the head sump container; at least one primary nutrient feed outlet line; wherein a first end of the at least one primary nutrient feed outlet line is attached to the head sump nutrient outlet and a second end of the at least one primary nutrient outlet line is attached to the root zone nutrient valved inlet of a first root zone container of the one or more root zone containers such that there is cascading fluid communication between the root zone nutrient valved inlet of the first root zone container and the head sump nutrient outlet; at least one primary nutrient return line; wherein a first end of the at least one primary nutrient return line is attached to the root zone nutrient return of the first root zone container and a second end of the at least one primary nutrient outlet line is attached to the at least one head sump nutrient return such that there is fluid communication between the root zone nutrient return of the first root zone container and the at least one head sump nutrient return; wherein the pump is connected to the head sump nutrient outlet and configured to pump liquid from the head sump container through the primary nutrient feed outlet line and into the one or more valved controlled root zone containers the system optionally being configured to be controlled by a computational control. The system of claim 1 wherein; the primary nutrient outlet line comprises one or more outlet spurs, each of the one or more outlet spurs providing fluid communication between the primary nutrient outlet feed line and root zone nutrient inlet of one of the one or more root zone containers via the root zone valve; and the primary nutrient return line comprises one or more return spurs, each of the one or more return spurs providing fluid communication between the primary nutrient return line and a root zone nutrient outlet of one of the one or more root zone containers.

3. The system of any preceding claim wherein the head sump nutrient outlet comprises a nutrient outlet directional valve, the nutrient outlet directional valve configured to control the direction of liquid flow through the head sump nutrient feed outlet to from the head sump unit into the primary nutrient outlet feed line;

4. The system of any preceding claim wherein the pump is a bottom suction submersible pump.

5. the system of any preceding claim wherein the head sump unit further comprises a waste outlet.

6. The system of claim 5 where in the waste outlet is an aperture connected to a waste pipe on to outside of the head sump unit.

7. The system of claim 5 or 6 wherein a pipe extends from the pump then splits into an outlet arm and a waste arm, the outlet arm connected to the head sump nutrient feed outlet and the waste arm connected to the waste outlet; wherein the outlet arm comprises an outlet valve and the waste arm comprises a waste valve.

8. The system of any preceding claim wherein the root zone nutrient inlet is positioned at a level higher than a set balanced nutrient level of the root zone container

9. The system of any preceding claim wherein the root zone nutrient outlet is positioned on a lowest point of a side of said root zone container.

10. The system of any preceding claim wherein each of the root zone containers are configured such that the root zone nutrient inlet is level with or above the growing medium such that liquid from the root zone nutrient inlet cascades into the root zone container onto the top of the root ball

11. The system of any preceding claim wherein the pump is further configured to draw liquid from the one or more root zone containers and back to the head sump container.

12. The system of any preceding claim wherein the primary nutrient outlet line splits into two or more primary nutrient outlets; wherein the number of primary nutrient return lines is equal to the number of primary nutrient outlets. The system of any preceding claim wherein the wherein the head sump unit comprises an adjustable auto top off valve. The system of any preceding claim wherein the growing medium is a net pot. The system of any preceding claim wherein the one or more root zone containers each comprise an air bubbler at the base of the root zone container.