I am currently using Copper Power in a 20 gal fish QT for a Royal Gramma and 3 x Talbot's damselfish. I dosed it according to the instructions (1 fl oz per 20g) and have done a 20% and 10% water change since dosing. Today I got my Hanna copper checker, and the concentration was 2.38 ppm. Copper Power recommends their concentration to be at 2.5 ppm for therapeutic treatment. Is this concentration too high? Will it harm my fish?