Deep water culture is a hydroponic system in which roots hang directly in a container of nutrient solution, kept oxygenated by an air pump and air stone. The plant sits in a net pot filled with clay pebbles or rockwool in the lid. It is simple, has few moving parts, and grows plants very fast when solution conditions are right.
In practice
A typical home DWC is a 15-25 L (4-6 gal) bucket per plant. Key targets: solution temperature about 18-21 °C (64-70 °F), dissolved oxygen well above 5 mg/L, pH about 5.6-6.2, and EC rising from about 0.6-1.0 mS/cm for young plants to 1.6-2.2 mS/cm in flower. Top up with water or weak solution as the plant drinks, and change or refresh the solution every 1-2 weeks. Warm, poorly aerated solution is the main cause of root rot (Pythium).
Don't confuse with
- RDWC: several DWC sites linked to recirculate through a shared control bucket.
- Kratky: passive, unaerated water culture with an air gap.
An air stone is a porous diffuser connected to an air pump that breaks air into fine bubbles in a nutrient solution, mixing it and helping maintain dissolved oxygen.A net pot is a plastic cup with slotted or mesh walls that holds a plant and its medium in a hydroponic lid, letting roots grow through into solution.Clay pebbles (LECA) are fired, expanded clay balls used as an inert hydroponic medium that drains freely, holds a little water and anchors roots.pH measures how acidic or alkaline a solution is on a 0–14 scale; in growing it controls nutrient uptake, with soil best near 6.0–7.0 and hydro 5.5–6.5.EC (electrical conductivity) measures how well a solution conducts electricity, a proxy for total dissolved salts; growers read it in mS/cm to gauge nutrient strength.mS/cm (millisiemens per centimetre) is the standard unit of EC for nutrient solutions; 1 mS/cm equals 1 dS/m and 1,000 µS/cm.Decay of roots by pathogens such as Pythium, Fusarium, Rhizoctonia or Phytophthora, usually triggered by low oxygen, heat and waterlogging around the roots.A genus of oomycete water moulds, such as Pythium myriotylum and P. aphanidermatum, that cause brown, slimy root rot, especially in warm hydroponic systems.RDWC (recirculating deep water culture) links several aerated buckets to a central control reservoir, pumping solution through all of them to keep conditions uniform.Dissolved oxygen (DO) is the amount of oxygen gas held in water or nutrient solution, measured in mg/L, and roots need it to respire and take up nutrients.A chiller is a refrigeration unit that cools hydroponic nutrient solution, keeping it around 18-21 °C so it holds more oxygen and root pathogens are discouraged.A reservoir is the tank that holds a system's water or nutrient solution, the place where pH, EC, temperature and oxygen are measured and adjusted.
