discouraged

So last month I got 6 pygmy cories to add to my 20gal community tank (relevant threads) with platies, zebra danios, and cherry shrimp. I really loved seeing them school at first. But, I don't think they're doing very well. Of the 6 I bought, 2 were unhealthy and died after a day or two. Another...

My daughter's fish is sick...I have really tried to educate myself being that I'm new. Water parameters are good at this time. Ph 7.5 ammonia 0 nitrite 0 NirAte 5.0ish Temp around 80* 3 gallon tank I now use prime. He is getting fed every other day a pellet and the occasional dried blood...