Hi I have a 26 gallon with filter, air, heater and I understand that I need to do a water change every week or two. I just bought 5 neon tetra, 2 glo fish, 3 platy, 5 molly, 4 male guppies and 2 female guppies, is house in the 26g tank (all small fish) (petco personal assure these fish will go...