When I did hydro, I made 6 five gallon buckets with 6†net pot lids. Temp in the reservoir averaged 65F. As you mentioned I was about 1†to 1 1/4†below the net pot and each bucket had about 3 gallons in it. Each with a 4†air stone, top feed seedling to harvest, circulation every 15 minutes for nutrients from the reservoir and an overflow back to the reservoir with 2 6†air stones in that reservoir. 6 plants=1543grams dried. It was a chore monitoring and measuring every couple days but the yield was huge.