Just tested it, the nitrates were indeed around 100pm. my kh was in the ideal range and everything else was the same. I did not put any more medicine in today. the fish still look the same. My water has a green tint in it from the fungus medicine i put in yesterday. I looked today at petco, no sign of the coppersafe stuff. I read the wardley stuff i have and it said something like not great for tetras. I have some tetras. should i not use it ?