I've just setup a small scale recirculating drip system, and am having issues with both ph control and smell. I'm using canna coco a + b, and GH ph down. I have the drippers set for 1 minute at lights on, and 1 minute at lights off. This time results in run-off for all the plants. The res is roughly 18 gallons, and there are 5 plants. I have a small water pump running 24/7 in the res to create constant movement. My issue is the res smells stagnant, maybe stale. Do I need a airstone in the res? Should I be letting the drip cycle longer? I have been reading through, but haven't found the answer yet. I am planning on switching to CNS-17, whenI'm done with the Canna. Will post pics in a few.