IWS Flood and Drain System

IWS Flood and Drain System is a fully automated feeding system that takes the strain out of tending to larger numbers of plants. This system has been a customer favourite for over a decade, and there are very good reasons for that: it’s simple to set up and run, it makes tending to commercial scale gardens quick and easy, it allows you to control feed times with complete precision, and come harvest time, it delivers the goods.

Aqua Inner Pot (holds 6.5 litres of medium). These inners feature drainage holes most of the way up – ideal for growing in clay pebbles.

  • Automatically feeds plants during user-set periods
  • Known for being one of the best yielding systems out there
  • Designed and manufactured in Britain!
  • Proven to deliver the goods – a customer favourite for years
  • Comes with the premium IWS minute timer for precision feeding
  • Represents superb value for money
  • Manufactured from tough, crack-resistant plastic
  • Choose from multiple different system sizes – from 6-pot to 48-pot


  • Flexi Tank – dependant on your choice of system
  • IWS Flood & Drain Brain Pot (otherwise known as the Controller Bucket)
  • Premium IWS Flood & Drain Minute Timer
  • Outer Pots
  • Aqua 6.5l Inner Pots
  • Copper Discs (to suit your choice of Inner Pot)
  • Pot Stands
  • Kit Bag (containing glands for outer pots, pipe-elbows, pipe-straights)
  • 13mm IWS flexi-pipe
  • Required but not included: nutrients, grow medium

Recommended but not included: Silver Bullet Roots (eliminates harmful bacteria in your system for trouble-free growing). Air Pump Kit (for oxygenating and mixing the nutrient solution in the IWS reservoir). Tank Heater / Chiller (to keep the nutrient solution from getting too hot or cold in the more extreme summer/winter months).

Our grow systems are designed to provide years of trouble free use, but for complete peace of mind, secure pipework that’s joined onto barbed fittings using jubilee clips or cable ties, and place run-off trays / floor secure sheeting underneath the system. It’s much better to be safe than sorry.

How IWS Flood & Drain Grow System Works:

The IWS Premium Flood & Drain is a complete nutrient delivery solution that can be arranged to suit virtually any grow space. It’s fully modular and adaptable, and can be upgraded to add new containers at any time.

Nutrient is pumped from the reservoir and out to the IWS Brain at user-specified times and durations (set on the IWS Minute Timer). The Brain is indirectly connected (via 13mm pipework) to the containers in the system; as it fills up, so do all of the containers. A float switch sits inside the Brain, which turns the nutrient flow from the tank off when the water level gets too high. The float height is the same as the top of the containers, preventing the system from ever flooding.

There are two parts to each container – an Inner and an Outer. The IWS Outer Pot connects to the pipework in the system, filling up with nutrient solution as the system floods. The inner pot sits inside the outer, and is perforated with holes. It contains the substrate and root-mass. As the outer fills up with nutrient the rootzone becomes saturated.

This premium version includes pot stands and the brilliant IWS Minute Timer, which allows you to control flood and drain cycles (sometimes called ‘ebb and flood’ cycles) with military precision.

This kit includes a custom-made IWS Flexi Tank. Flexi Tanks have been tested to absolute destruction and have never faltered yet. It offers all of the functionality of a standard water butt, with the ability to pack it away into a tiny space for easy transportation.

Which System Suits My Space?

We recommend allocating at least 30cm² – 40cm² to each container. Here’s a rough guide to the minimum space requirements for each system:

6-pot: 1.5m x 1.5m

12-pot: 1.5m x 3.0m

24-pot: 2.4m x 3.6m

36-pot: 3.6m x 3.6m

48-pot: 4.8m x 3.6m

If possible, we recommend allocating 40cm² – 60cm² to each container to give yourself plenty of room to tend to plants.

It’s easy enough to do the maths. First, work out the total area. For example:

2.4m x 3.6m = 8.64m²

Then divide the total area by the area that you wish to allocate each plant:

8.64m² / 0.6m² = 14.4 plants (round this to the nearest whole number)

If you’ve already got a particular size of system and you want to know how much room you’ll have per plant in a given area, divide the total area by the number of plants. For example:

8.64m² / 24 plants = 0.36m² per plant.

How to Use the IWS Premium Flood & Drain Grow System

The system is simple to put together and use. You will find the following items useful: a sharp knife or scissors (for cutting pipe), an adjustable spanner (for tightening nuts), and a container of half-boiled water (for softening pipe, making it easier to fit onto connectors). You will also need a timer or stopwatch to find the correct flood duration once the system has been put together.

The brain pot and the pot stands need to be installed on the same surface. The surface also needs to be level otherwise the system will either under or over-fill the pots.

Remember to keep your system clean and free of salt build-ups by using a product such as Dutch Pro’s Keep It Clean or H&G’s Drip Clean.

Preventing Water Damage: Even with a carefully set up hydroponic system, accidents can happen, often resulting in a considerable amount of water to be released onto the floor. Plan ahead and plan for the worst. For example, sit your system in a high-sided garden/gravel tray, or use our floor-secure sheeting on your grow-room floor. It can be fitted so that it rides up each wall by a few inches, creating a “floor-basin” which could help prevent a huge amount of water damage if the worst should ever happen. In this regard, it is much better to be safe than sorry.