So i have a 20 gal tank and I filled it with water and decor and such yesterday. I put in AquaSafe and Start Zyme, and let it run overnight, the water is perfectly clear and my levels are fine so i put a sucker catfish in there. he is doing fine and all looks well. So heres my question, i have 2 standard under gravel air pumps and a 4 inch 'bubbler bar' but the air pump i have only allows 2 of them to work a full capacity or 3 to work at half capacity. So should i just use 2 at full or 3 at half?