Micronutrients are the nutrients that are used in smaller quantities by the plant.
– They are calcium (Ca), sulfur (S), magnesium (Mn), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), and boron (B).
Macronutrients are the nutrients that are used in large quantities by the plant.
– They are nitrogen (N), phosphorous (P), and potassium (K)
Not all water is created equal. When we drink different waters, we experience their distinctive qualities as different flavors. The mineral, carbon dioxide, and oxygen content of water vary substantially, and affects your plants.
Three key measurements of the water composition are its “alkalinity”, its “pH” and its content of “dissolved salts”.
Alkalinity is the ability of the water to buffer acids. When water contains dissolved solids/minerals the pH is not affected as much by the addition of fertilizer. When water is pure and contains no minerals it is called soft water. This water has little or no buffering ability so its pH is very changeable.
pH is a measure of acid-alkalinity balance. A pH between 5.3-6.5 is what plants like best. The pH of tap water may change seasonally. Test it regularly. The pH changes when the water company flushes its system.
Dissolved salts are the mineral content of the water and is usually expressed as parts per million (ppm). This can be measured using electrical conductivity (EC) meters. A reading of 125-150 ppm for your water is a good starting point because it represents some buffering ability , but not to much that large amounts of minerals have to be added to adjust pH.
NOTE – When you irrigate the plants make sure that you don’t shock the roots with water that is either too cold or too warm. Make sure that the water is in the temperature range of 65-75 F or 18-24 C.
Hydroponics is the method of gardening in which plants are supplied with nutrients through the water solution. Hydroponic systems vary in their complexity and the amount of care that they require.
Gardeners have a choice of systems to accomplish this. Deep Water Culture (DWC), Drip Systems, Ebb and Flow (Flood and Drain), Nutrient Flow Technique (NFT), Reservoir and Wick Systems are all considered hydroponic gardening.
Systems fall into one of two categories : Passive Systems or Active Systems.
Passive Hydroponic Systems use capillary action to draw water through the planting medium. As water is used it creates “tension” which pulls water molecules up. It supplies plants with as much water as they need. Passive systems include reservoir systems, wick systems, and capillary mat systems.
Active Hydroponic Systems use pumps to move fresh water/nutrient solution to the plants so that the environment is refreshed by a solution on a timed schedule. Active hydroponic systems include deep water culture (DWC), drip systems, ebb and flow systems and aeroponic systems.
Active Hydroponic Systems use submersible water pumps to deliver fresh water/nutrient solution to the plants so the environment is refreshed by a solution that hasn’t been mined of nutrients and oxygen. Active hydroponic systems include deep water culture (DWC), ebb and flow (flood & drain), drip systems, and aeroponic systems.
Deep Water Culture (DWC) systems keep the roots bathed in an oxygenated water/nutrient solution. Mesh baskets filled with leca are usually used for this system. The baskets are suspended above the water level and the roots hang down into the oxygenated water. The roots have total access to water, nutrients and oxygen which are dissolved in the water. Large air pumps supply air through air stones in the reservoir keep the solution oxygenated.
Ebb and Flow systems use a reservoir to hold the water/nutrient solution and a tray to hold the plant containers, or rockwool cubes with the plants in them. Water/nutrient solution is periodically pumped into the tray, and then allowed to drain back into the reservoir. The planting medium holds enough moisture between watering’s to meet the needs of the plants. Oxygenate the reservoir with an air pump and air stone and maintain a temperature of between 68F-73F using a submersible water heater.
Drip Hydroponic Systems work by delivering water slowly to the planting medium or soil using an emitter or dripper stake. These are installed at the end of the 1/8″ irrigation tubing, which is connected to the 1/2″ hose coming from a submersible pump. The submersible pump delivers water from a reservoir, through the 1/2″ hose , then through the 1/8″ irrigation tube to the emitters or drip stakes, which are positioned above or in the planting medium. Every plant container or rockwool cube is serviced by its own emitter or dripper.
Aeroponic Systems spray an atomized mist of water/nutrient solution directly on the roots. The tiny droplets of fast moving water are well aerated so they constantly replenish the roots with oxygen. The water/nutrient spray also delivers nutrients in an absorbable form which encourages extremely fast growth. In both cloning machines and plant systems the plants are held in small baskets, usually filled with leca or rockwool. You must use a strong submersible pump in order to get a fine mist. Less powerful pumps result in a coarser spray. Aeroponic systems leave little room for error. If the pump quits or the misters malfunction the plants can go down in a matter of hours. This is why most aeroponic systems are only used in small reliable clone machines.
Passive Hydroponic Systems use capillary action to draw water through the planting medium. Systems included in passive hydroponics are reservoir systems, wicking systems, and capillary mat systems.
In a reservoir system plants are grown in containers containing a combination of growing medium. Fast draining media like leca, or perlite are usually on the bottom of the containers and the top portion is filled with a hydroponic mix such as a vermiculite/perlite mixture, or peat moss mixes (Pro Mix, Sunshine Mix).
The planted containers are then put into a reservoir. Almost any tray can be used as a reservoir. Tupperware storage bins or kids swimming pools make good and affordable reservoirs.
Water/nutrient solution is manually poured into the reservoir which contain the plants. This solution is replenished by the gardener as the plants need it. This is a system that requires daily monitoring so as not to let the plants dry out.
A capillary mat is about 1/4″ thick and are made from coco or soft polyester. This mat has great wicking ability. When containers are placed on the mat it compresses. This indent is below the water level allowing plants to draw up the solution as they need it. Less water is put into the reservoir and daily monitoring is recommended.
In a wick system the plant container is held above a reservoir. Lengths of wicking material hang from holes in the bottom of the plant container. The other ends of the wicking material hang into a reservoir filled with the water/nutrient solution. Capillary action draws water up the wick to the roots The wick system is self regulating, and the amount of water delivered to the plants depends on the amount of water lost through evaporation and transpiration. As long as the reservoir has water, the plants are being watered.
