Whyle we have been building our green house allot of water collected in our 2 / 700 gal stock tanks and there was allot of mosquito larva. We introduced ten gold fish in each tank and they got the mosquito problem under control. The water is green and we do not feed them. My question is should I cycle this waterempty the tanks and refil with fresh water? Is the established bacteria of any benefit or detriment?