So i have just under 10 twenty watt pumps, active aqua by hydrofarm, and the 20 watt says it pumps 45 lpm of air. The 60 watt says it pumps 70 lpm of air. The 112 watt pump says 110 lpm. Think i got the numbers right.. anyways disregarding pump price, wouldnt it be the most efficient to use the 20 watt pumps? More liters per minute of air per watt right? And watts are proportional to electricity cost right? Am i wrong? Does the higher psi of the larger pumps factor in? I would think i should go by lpm tho... i currently have 9 20 watt pumps running 7 18 gal totes