0,0,0 nirates More fish?

Well, I currently don't have BBA, and plan to get more fish to increase the nitrate production to possibly more than the plants eat (or whatever plants do to nitrates.) I'm going to venture a guess that adding a fish now is a safe bet.

Which leads to this other post I made. I plan to move the rosy's out after I get a 20+ gallon in mid august, but should I add the fish to the 15 gallon for the next month that I plan to keep after the rosys leave or add more rosys so there is a school then move them all over to the new tank in august?
 
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