1 watt per gallon is right. I have a 35 watt pump for 5 five gal buckets and a 20 watt for a 5 gal and a ten gallon. I wud not use the hydrofarm pump. It is a scam. 8 watts! Get on eBay and buy a 50 dollar 20 watt or a 60 dollar 35 watt. These are the real comercial airpumps and work very very well. Only thing is sometimes airstones are not big enough. Like for my twnety watt I have more that one airstone. Not just 20 watt in one 1 inch airstone! Cant handle it. I notice direct increases in growth, like when you lower feed times in ebb and flow and get a jump, when I added multople airstones to high powered lines. I read the 80 dollar hydrofarm add once and was depressed to see that they pulld an 8 watt scam. 35 watts is like 60lph I think. I
follow watts tho so I firget. One watt a gallon. Helps with heat too. Get one with a metal manifold. Beter qualtiy.