You can use your resivour as your controller and just keep it level w/ the buckets,just do as latewood said and use a pump to empty out the system. You can also switch the feed pump(at nute change time) to your empty out drain line

BTW. Shut off valves are lifesavers in the long run. I would run one at the begining of the drain line and one at the end of your empty out drain line.
The White Snoop Reviewed by The White Snoop on . How to recirculate a 4 bucket waterfarm system with a res and controller? I was told the feed hose should be a smaller diameter than the drain hose. 1/2" flexible tubing connected to the bottom of each bucket for draining. Already in place. The stand alone res of the waterfarm has a 1/2" hole at the bottom. I am going to put a water pump inside to push the water out. Then use a diameter changing adapter on the outside and either flexible 1/4" or 3/8" for a feed tube. I'm going to drill a hole 2/3 of the way up on each lower bucket for the feed line. Not done Rating: 5