Ok so I'm still trying to figure some things out. I got a Penguin 1140 PH (300GPH) at Petco yesterday but was wondering if the ZooMed powersweep from Petsmart would work better..? I searched a bit and saw a few comments that the powersweep is not reliable. Should I stick with the Penguin? The tank is 37 gallons. Do I need to get a second PH or is the one enough? If I have to get a second could I go with a less powerful one (cause they're cheaper)? Thanks!