Are you looking for an inexpensive hydro system that is simple to set up, needs no electricity, takes little time to maintain, operates for days without your presence, and is very forgiving? If so, read on. If not, invest in an expensive system as temperamental as a high performance sports car and requires constant monitoring.
The System and the Theory
The easiest hydroponic system to build and maintain is the wick system. Its cousin, the reservoir system, is a close second. Here’s how these systems work: Starting from the bottom up, there is a tray filled with water-nutrient solution; this is your reservoir. Inside the reservoir sits a plastic coated wire container, Styrofoam or wood block about the height of the tray. A specially prepared plant container sits on the tray or block. A wick hangs from each of the plant container’s holes.
The system works by drawing moisture from the reservoir up through the wicks to the container and planting mix inside it as the water is used by the plant or evaporates into the air. The system is self-regulating. It draws up only as much water as is needed through capillary action, which is the same force that draws moisture up a tissue. As long as there is water in the reservoir, the plants will never go dry.
1) THE TRAY/RESERVOIR:
A tray at least 15 cm in height with enough of an area to hold the container or containers in your garden. The reservoir can be sized for a single or multiple plant containers. Shallow dish trays, plastic storage containers, Styrofoam coolers and kiddie pools can all be used as reservoirs.
2) CONTAINER SUPPORT:
Blocks or trays to hold the containers over the reservoir. They should be wide enough to keep the containers securely upright. Among the items I have used as supports are wooden or styrofoam blocks, inverted plastic coated wire trays, flat wire trays that rest on the reservoir walls, and shipping pallets.
3) PLANTING CONTAINERS:
Standard plastic planting containers. Any size can be used. As with standard planting techniques, choose the container based on your desired plant size. Use small pots for sea of green gardens or large containers for bigger plants.
Braided nylon wick 1-2 cm in diameter. For 15-20 cm pots, 1 cm wick works well. For 25-30 cm containers use 1.5 cm wick, and for larger containers use 2-2.5 cm wicks. Don’t use cotton wicks as they will rot. Other rope materials don’t exhibit capillary action.
For a completely hydroponic system you can use #3 grade vermiculite, vermiculite-perlite 50-50 mix, horticultural clay pellets, or pea sized red lava. I have used all of these mediums and they all work well.
You may wish to try a hybrid of hydroponic and planting mediums that is often used in the commercial container plant industry. It is called fertigation. Use a non-nutritive mix, such as Sunshine Mix #4 or #8. This type of mix will not make any nutrient claims on the packaging. Fertigation is more forgiving than straight hydro because the medium itself and the microorganisms that thrive on its surfaces hold the nutrients and buffer them, helping prevent an imbalance.
Another option is to use a planting mix that has been enriched with nutrients. There are some very high quality mixes that are enriched with organic nutrients that break down into plant usable salts over several months. Although the macro nutrients—especially nitrogen (N), but also phosphorous (P) and potassium (K)—may be exhausted before the gardening period is over, the organic fertilizer supplements will supply the minor nutrients throughout the growth period. The water-nutrient solution will provide macronutrients throughout the growing period so the plants will have redundant sources of nutrients. This is an almost foolproof method.
There are a few soils enriched with time-release fertilizer. They have all the nutrients that are needed throughout the growth period.
The nutrients that you supply will supplement these nutrients.
Use a hydroponic fertilizer. They are all completely soluble in water
and all contain appropriate amounts of NPK. All the organic hydroponic fertilizers I have used promote microorganisms, so they ferment in the reservoir. Instead, use standard hydroponic fertilizers suitable for the plants’ stage of growth.
* pH Test Kit: Although there are many methods, a pH meter and pH up and down solutions will help keep the pH in the proper range.
* Watering Can
* Twenty Liter Bucket
* Small submersible pump to circulate and aerate the water.