Yes. Roots need oxygen to breathe, and in water the oxygen supply is limited. Most hydroponic systems add oxygen by moving the solution, exposing the roots to air, or using an air pump.
Signs of Low Oxygen
Roots that turn brown, feel slimy or smell bad can mean the water has too little oxygen, especially if it is also warm. Slow growth and wilting can follow.
How Systems Supply Oxygen
- Air pump and air stone: bubbles add oxygen to the solution.
- Air gap: in passive systems such as Kratky, the falling water level leaves roots exposed to air.
- Moving film or flood and drain: the solution moves past the roots, and air reaches them between cycles.
Related guide: Hydroponics Basics.
