Ebb and flow: how flood and drain works
A pump floods the tray on a schedule, then the solution drains back.
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How it works
In ebb and flow, also called flood and drain, plants sit in a tray above or beside a reservoir. On a schedule, a pump floods the tray with nutrient solution. Then the solution drains back to the reservoir.
The timer
A timer switches the pump on and off. The timer, the pump, and their plugs are electrical parts in a wet system. Keep plugs, cords, and connections away from water, and follow every maker's instructions.
GFCIs
CPSC says a GFCI "is designed to protect people from severe or fatal electric shocks," and that ground fault protection is used "especially for circuit outlets in particularly vulnerable areas such as where electrical equipment is near water." Use a qualified electrician for any wiring.
Media in the tray
The plants in the tray sit in pots or in a growing medium such as clay pebbles or stone wool, as the maker describes. Our growing media guide covers the names.
What we do not say
We do not give flood times, schedules, or nutrient strengths. Follow the maker's instructions and the nutrient label. Results vary.
This is general information, not legal, electrical, or safety advice.
Sources: CPSC, GFCI Fact Sheet (Pub. 099).
FAQ
General information only. Water and electricity are a dangerous mix: keep plugs, cords, and connections away from water and follow every maker's instructions. CPSC says a GFCI "is designed to protect people from severe or fatal electric shocks" and to test every GFCI "At least once a month." Use a qualified electrician for any wiring. Keep nutrients and other chemicals away from children and pets. In an emergency, call 911.
Next: drip systems
Tubing, emitters, and a pump.
