My tank is like 2 months old. I have Guppys, Danios, Platys, and neon tetras. I had gone on vaction and had someone caring for my fish. I think that they were feeding them to much. Cuz when I came home the tank was real dirty and one was dead. I did a 20% water change and vaccuum the tanks bottom real good. But I'm still losing fish I had the water tested and they told me that the ammonia was real high. So i did another 20% water change. but fish are still doing bad. The Guppys have arches in there tails and I have a Platy that is dying. PLEASE HELP!!!!!!!!!!!!!