I have a 10 gallon tank with Angel fry. There was 400 in there but now I have about 150, many fish have died. I can't figure out what I am doing wrong. I know I am doing the water correcxtly. I started with two days of fresh water and hydrogen Peroxide. 10 drops per gallon. Then I changed to aged water and DeChlor. My water tests fine Nitrates 0, Nitrites 0, Hardnes hard alkline 160 and my PH is 7.6. I checked my house water for PH and that is also 7.6. I am at the point where I change the water every other day. Last night I lost 66 of the fry. What am I doing wrong. Thanks