Someone help me understand why this happened? This is very confusing to me.
1) My guppies were doing great for several months, they had babies and 1 male survived and grew up.
2) Then my fancy guppy Hedwig starting to lose chunks of his tail fin. I though maybe the other male was fighting with him so I gave away the young male and got 2 more females from the fish store.
3) 2 days later one of the new females was dead.
4) 1 week later another baby guppy was missing the entire rear half of his body, including his tail, and the wound was covered with white fuzz. I had to euthanize him, he was barely alive and seemed like he was in pain.
5) Now my fancy male Hedwig is not able to swim straight ... he is at the surface with his head pointing up and his tail pointing down. Barely alive ... I think he will probably be dead in the morning.
I don't understand what I did wrong. The tank has been set up for more than 6 months and is fully cycled, ammonia 0, nitrite 0, nitrate 10ppm, ph 7, temp 78 degrees. I don't understand why my fish keep dying ... if anyone has any insight plz let me know. I seem to be better at keeping plants alive than fish. This is very sad to me. :(