So I got some fish last night for a new 20 gal tank, the cycle was good, PH is in the 7.9-8.0 area, ammonia is very low, 0 basically, maybe very slightly into the 0-0.25 ppm range. Nitrites and Nitrates are 0. I had the local aquarium store (a good store, not Petco, Petsmart, etc), a good...