BASIC PRINCIPALS; Plant foliage requires light, oxygen and carbon dioxide. Plant root systems require water, nutrients and oxygen. When plants are grown normally water leeches nutrients from the soil and carries them to the roots. The water and nutrients are taken up by the roots to feed plant growth. Soil drainage then allows water to be replaced by air in the gaps between soil grains. This supplies the roots with oxygen.
In hydroponics the nutrients are dissolved in the water. Soil is replaced with a growing medium to supply the roots with water, nutrients and oxygen. Hydro juice (nutrient solution) can be drip fed to each plant, it can also be used to regularly flood the root chamber, then drain out. Both methods require a pump and timer to circulate the nutrients through the roots and are covered by these diagrams and notes. Roots can also be grown in the air by spraying roots with a fine mist of hydro juice, or grown in the hydro juice and the solution aerated under each root mass with an air pump. With both of the second two methods the plants must secured at the base of the stem or something.
The hydroponic system described does work and is suitable for any plant with stringy roots. I have not tried it with any bulb plants or plants such as orchids that require fungus or mold in the soil to grow. This method is similar to Nutrient Film Technique (NFT) the thin Rockwool slice acting as a capillary mat. This eliminates the need to have flat bottom the root chamber and to level the bottom of root chamber, making easier and cheaper to set up.
This method will get the most vigorous growth if each plant has it’s own continuos drip feed. The dripper is positioned drip on roots growing from the base of the seedling block, the roots will grow thick, hairy and compact under the dripper. 4L per hour dripper are used however their drip rate depends pressure, this is effected by height and size of the drip feed tank. The drip rate will slow as the tank empties.
Feeding can also be achieved with faster dripper at the top of each top end of each side of the root chamber. The plants grown like this had a large root mass, the roots of three plant taking up about a third of the root chamber. With the timer I had could only flood the root chamber every 4 hours, the growth rate was similar to the last. The growth rate will improve by flooding every hour or even less. After the root chamber is flooded it should drain to a trickle in a few minutes.
STARTING PLANTS; Soak seeds in damp paper or cotton wool, cover seed with damp paper or cloth, drian off excess water and don’t allow to dry out. When the seed root is 2 – 5mm. long place the seed root first in the small hole with tweezers (fig.3). Make sure the root is protected by the open jaws of the tweezers and that the seed or root isn’t squashed. Then place seedling block hole up on a plate and wet Rockwool until it won’t take any more water. Keep the plate on an angle for drainage, but the seedling blocks shouldn’t dry out too much and seedling should come up in a few days. Seedlings can stay on the plate until roots grow from the bottom or sides of the seedling block (fig.4).When this happens seedling are ready to transplanted on to the Rockwool mat in the root chamber. (Before the seedling blocks go into the root chamber the rookwool is soaked in water 24 hours then with hydro juice at half strength.) Roots will grow from seedling block, through and along the under side of the Rockwool mats. Place three to eight plants per side, evenly spaced along the slot, and it will soon grow into mass of green. When the system is operational and plants are growing, the inside of the root chamber should have a rich earthy smell. Three or four plants if your growing them big (outdoors ), eight if your growing fast and flowering early ( under lights ).
When the roots grow from the bottem or sides of the Rockwool block it’s ready to transplant into the grow tube. Once the roots have grown into the mat tou can hit them with full stength hydro juice. Light proof plastic should be used to cover the top of the root chamber white side up, this is to stop green slime growing on the rockwool. This can only be done when the plant is tall enough, take care not strain or damage the plant.
Many seeds require special conditions to germinate. For example, most garden vegetables and herb seeds need to remain damp or wet for some time.
Seeds can be germinated in a hydroponic grower, and often they germinate even better than in soil.
Most seeds are placed below the surface of the media. A suggested placement is from ½ to 1 inch below the surface. This keeps the seed very moist and will give it some feel for when the light is and where the dark is. The root of the plant will grow down towards the dark and the water, and the plant stem and leaves will go towards the light.
Many seed packets include instructions for soil and mention how deep to bury the seeds. They can be planted at the same depth in hydroponics.
Some seeds, like beans and corn, will germinate in just a few days. Some others, such as tomato, bell pepper and herbs may take as long as two weeks until they appear. Growers with seeds should be watered each day although no plants are showing. If you do not see any sign of life after two weeks, it is best to replant the grower.
Occasionally the grower root area will be so cold or so dry, the seeds will not germinate.
To germinate very small seeds like many herbs, a special form of germination may be required. One way is to start the seeds between two pieces of paper or a towel soaked with water. The towel is kept moist each day.
Germinating some types of seeds is more complicated than just soaking in water. Some seeds need to be damaged in some way to germinate, and others are specialized to respond to periods of temperature or light. If there something you would like to grow, it might help to learn what the seed requirements are to germinate.
Other Methods of Reproducing
Some plants can reproduce from cuttings. This means cutting a small part of the growing tip of a plant, pulling off the bottom leaves and sticking the cut end into the growing media. Some of the plants that can be reproduced from cuttings are basils and many of the herbs.
Garlic reproduces from individual garlic cloves. Some of the garlic in the grocery store is treated and will not sprout. An organic garlic is more likely to sprout.
Potatoes are grown from a planted potato. The potato can be cut into pieces or planted whole.
ROOT CHAMBER; The Root Chamber is made from 90mm. PVC storm water pipe. This type is used for all new building constructions so off cut are about. A selection of 90mm. PVC storm water pipe and 90mm. fittings are available at large hardware stores. Fittings include right angles, tee junctions, end caps and others. These can be used to make the root camber suit any room. The root camber show in Diagrams (fig.5,6,7) is made with two lengths about 1 miter for the sides, 2 lengths about of 600mm. for the ends and 4 right angles for the corners. PVC pipe glue is used to make all joins water tight. A slot is cut in the top of each side providing access to change growing medium and remove root mass. Holes instead of a slot may be used for each plant but another way of access must be used. A drain hole or holes are drilled in the bottom of one end of the root chamber and a flood hole is drilled in the top of the other end. The root chamber is mounted on an angle with drain end below then the flood end. This is to ensure that the roots don’t get water logged. Too much of an angle will cause the Rockwell and roots to dry out at the high end.
FLOOD AND DRAIN.
A flood and drain system requires a timer, a pump and a drain tank to catch the hydro juice. Hose is run from the bottom of the drain tank to the pump inlet. Hose is run from pump outlet to the hole in the top of the flood (high) end of the root chamber. The pump inlet is below the bottom the drain tank. As the drain tank is filling hydro juice flows through to the pump inlet through the pump and up the flood hose till level with the hydro juice in the tank. This is to prime the pump as the pump can’t suck air, it can only push out what flows in the inlet. The timer runs the pump for 1 minute and the hydro juice fills about half the root chamber. If chamber over flows increase size of drain holes. If a hose is used at the drain end, it must not cause hydro juice to stand at the drain end. A recycling type bin is ideal for the drain tank (see end of Drip Feed section to attach hose to drain tank). Putting the pump on the floor and the drain tank on bricks should raise it enough prime the pump.
EBB AND FLOW (FLOOD AND DRAIN)
The Ebb and Flow system works by temporarily flooding the grow tray with nutrient solution and then draining the solution back into the reservoir. This action is normally done with a submerged pump that is connected to a timer. When the timer turns the pump on nutrient solution is pumped into the grow tray. When the timer shuts the pump off the nutrient solution flows back into the reservoir. The Timer is set to come on several times a day, depending on the size and type of plants, temperature and humidity and the type of growing medium used. The Ebb and Flow is a versatile system that can be used with a variety of growing mediums. The entire grow tray can be filled with Grow Rocks, gravel or granular Rockwool. Many people like to use individual pots filled with growing medium, this makes it easier to move plants around or even move them in or out of the system. The main disadvantage of this type of system is that with some types of growing medium (Gravel, Growrocks, Perlite), there is a vulnerability to power outages as well as pump and timer failures. The roots can dry out quickly when the watering cycles are interrupted. This problem can be relieved somewhat by using growing media that retains more water (Rockwool, Vermiculite, coconut fiber or a good soiless mix like Pro-mix or Faffard’s).
Drip Feed System.
This feed system has a dripper for each plant. Dripping the hydro juice directly on the top of the root mass should stop the plant from sending out long roots in search of food. Resulting in more growth on top or so the theory goes. The drip system uses a drip feed tank about one meter above the drippers and reticulation system.
Reticulation is via 13mm. poly tube to just above the root chamber. A hole is punched in the 13mm. tube. A 4mm. adapter is screwed into the hole. Then 4mm. poly tube is attached to the 4mm. adapter. A dripper is attached to the other end of the 4mm. tube. The 4mm poly tube should be kept as short as possible so there is enough pressure to start the drippers. Barbed right angles and tee’s are used to route the 13mm. poly tube close to each plant. The top of the 13 mm. poly tube is about 50mm. below the bottom of the drip feed tank. A 13mm. to snap-on adapter is fitted to the top of the 13mm. poly tube. If the 13 mm. poly tube is positioned at right angles to the slot and the 4mm. adapter, 4 mm. poly tube and the dripper positioned over the slot. Any leakage at the joins in the poly tube will drip into the slot preventing loss of hydro juice.
A 42 liter plastic garbage bin and lid is used for the drip feed tank. Snap-on fittings and 13mm. garden hose connect the bottom of the drip feed tank to the to 13mm. poly tube. They also connect the pump outlet hose to the top of the drip feed tank. A Stop Snap-on is used where the garden hose connects to the Snap-on adapter on the 13mm. poly tube. This prevents the hydro juice flowing from when the Snap-on is removed from the 13mm. poly tube. To convert from flood and drain to drip feed. Move the pump outlet hose from the flood inlet on top of the root chamber, to the top of the drip feed tank.
Snap-on universal sprinkler adapter are used to connect hoses to the side of the drip feed tank . These are a Snap-on to 13mm. thread adapter. There is also a 20mm. thread that screws onto a 13mm. thread. A hole no larger than the 13mm. thread is drilled in the side of the tank. The 13mm. thread is pushed through the hole from the outside of the tank. Now the 20mm. thread is screwed on to the 13mm. thread inside the tank creating a water tight seal. Make sure the hole is away from obstructions inside the tank that would prevent the 20mm. thread from attaching to the 13mm. thread. This method is used for all tanks and also for the pump outlet hose connection to the top of the flood end of the root chamber.
Drip systems are probably the most widely used type of hydroponic system in the world. Operation is simple, a timer controls a submersed pump. The timer turns the pump on and nutrient solution is dripped onto the base of each plant by a small drip line. In a Recovery Drip System the excess nutrient solution that runs off is collected back in the reservoir for re-use. The Non-Recovery System does not collect the run off.
A recovery system uses nutrient solution a bit more efficiently, as excess solution is reused, this also allows for the use of a more inexpensive timer because a recovery system doesn’t require precise control of the watering cycles. The non-recovery system needs to have a more precise timer so that watering cycles can be adjusted to insure that the plants get enough nutrient solution and the runoff is kept to a minimum.
The non-recovery system requires less maintenance due to the fact that the excess nutrient solution isn’t recycled back into the reservoir, so the nutrient strength and pH of the reservoir will not vary. This means that you can fill the reservoir with pH adjusted nutrient solution and then forget it until you need to mix more. A recovery system can have large shifts in the pH and nutrient strength levels that require periodic checking and adjusting.
12 Plant Patio Table Garden System.
Drill the 12 holes for the bottles and two in the center for the overflow pipe. Make sure you drill between the braces under the table.
The 1/2 inch PVC pipe is hidden under the table where it isn’t seen from the top.