My moms tank has cichlids, and some of them have fin rot. We put some medication in for fin rot and other diseases twice, and it didnt work. A few weeks later she bought the API Tetracycle medication and all of her fish, even the healthy ones, went to a corner of the tank and sat at the bottom. They were rapidly moving their fins and looked like they were going to die. One of them even looked like it was tilting to the side a little bit. We immediately did about a 20% water change. A few of them started twitching weirdly, like a twitch in their head to their middle almost? Although After about 2 minutes they began to look better. Within 5-10 minutes they moved out of the corner and started to head to the middle of the tank where they usually swim and started acting more normal.
Does anyone know what this was? Why it happened?
We followed all the directions on the package so i dont understand why this happened..