Your experiment will work just fine, Ive done it before. What I will say is, delivering air via a stone will increase plant growth big time! Its very noticeable. Grow two pots, 1 without a stone and 1 with a stone, you’ll see. In a 5 gallon pail almost any stone will work. I used a 6" long aquarium stone, my plant grew like crazy! Trust me though, once they get about 2 feet tall the solution goes pretty fast. I had a 5 gallon pail pre mixed and an empty one ready for the transfusion on standby. Ph will drift so dont be surprised. The drift isnt really a bad thing because plants have access to different minerals that way but try to keep it within an acceptable range.
