Cool. Then you should be able to keep a lot of fish, because you are on top of your water parameters. I would definitely get a different filter, I had terrible luck with my U4, my water was always spiking. How about 1 pearl gourami, 1 bosemani rainbow, 1 moonlight gourami, 5 cherry barbs, 8 kuhli loaches, and a few snails. Or you could do a South American cichlid tank with 1 angel, 1 German blue ram, 1 keyhole, 8 neons, and a bushy nose Pleco.