Well, I talked to a person at the local Petco and they told me to let it run for a night then come back to get fish...I wasn't exactly sure this was correct but when i returned the next day i talked to another 'specialist' and they suggested i get a small number of fish to put in, and they suggested platys. So I got the number they suggested (3, 1 bumblebee platy, 1 panda platy, and 1 sunset fire platy.) they seem to be doing fine, my water clouded up yesterday but this morning it was less cloudy then before.