The IWS flood and drain system works by flooding all the pots up to the same level to fully saturate the growing media, it then 'sucks back' all the nutrient solution via the brain bucket to the main reservoir. You simply set the frequency and duration of the floods based on plant size and stage of growth, growing substrate being used and size of system.
The incredible IWS PRO system floods and drains faster than any other flood and drain pot system thanks to the larger pumps and bigger pipework. The larger pipework also prevents root blockages. Comes complete with the IWS remote minute timer for accurate control of flood times and pot stands for better drainage.