Been testing my water at the same time each day. My ammonia is reading right at 0.50 ppm on my API Test Kit. The Nitrate registers maybe between 5.0 and 10 ppm. My ph level was around 6.4 to 6.6 and my Nitrite was 0. I know that my tap water has Nitrate in it because I tested it last week. However, I did my partial water change yesterday having done about a 40% change using Bottled Spring Water. My numbers are the same. Is there something I'm missing? Are these numbers toxic to my fish?