IWS Flood & Drain Systems

IWS Flood & Drain is the system most UK growers step up to when hand watering stops being practical. Pots sit in a tray, the Brain controller floods them from the reservoir on a schedule, and everything drains back under gravity. One tank, one pump, one controller, however many pots you are running.

How it works

1. The Brain unit opens a valve and the pump fills the pots from below.
2. Water rises to the height set by the standpipe, then holds.
3. The Brain closes, and everything drains back to the reservoir.
4. Air is pulled down into the medium behind the falling water – that oxygen recharge is the whole point.

What you get

• Even feeding. Every pot sees the same solution at the same time. No blocked drippers, no plant quietly missing out.
• Scales cleanly. 12, 16, 24 and 48 pot configurations off one reservoir.
• Very little to go wrong. One pump, one valve, one controller.
• Hands off. Fill the tank weekly and check EC; the system does the rest.

What to run it in

Clay pebbles are the classic choice – they drain instantly and hold air. Coco works with shorter, more frequent floods. Heavy soil does not; it stays waterlogged and defeats the design.

Getting it right

• Flood to about two thirds of pot height, never to the surface – a wet top invites algae and fungus gnats.
• Check the drain is not restricted. Slow drainage means roots sitting wet, which is the opposite of what you bought the system for.
• Watch reservoir temperature. Everything returns to one tank, so one problem becomes every plant's problem. Under 22°C – see water chillers.
• Run beneficials to suppress root disease in a shared reservoir – see beneficials and inoculants.

Related

See IWS spares and components, Brain pots, Brain control units and IWS AutoDrain. Compare with all flood and drain systems, DWC and bottom fed systems.

Why buy IWS from The Hydro Bros?

We are a hydroponics shop in Croydon and we build these to order. Tell us your tent size and pot count and we will spec the tank, pump and pot number together. Discreet UK and European delivery, and excellent customer reviews on Trustpilot.