I have a 45-gallon tank. I have a female Reeves turtle. There are fake plants in the tank, pebble substrate, two large filters, a bubbler, an above-tank basking platform for my turtle, a heater, and fake moss rocks in my tank.
I've had my tank running for almost 2 years now. I am certain that it's cycled, though I don't have anything to test the parameters.
I got new fish today from a lady who was moving. I got 11 neon tetras, this transparent tetra, two striped catfish (they aren't actually catfish, though. They look like large, tan tetras with a black stripe going through the middle of their body horizontally), and a little water snail.
I had the fish in bags. Once I got to my house, I floated the bags in the tank for thirty minutes. I then scooped the fish out of the bag and put them in the tank. For about an hour, they seemed fine. The "catfish" swam around together and the neon tetras schooled. Eventually, the "catfish" went their separate ways and hung at the bottom of the tank. I did some homework. I checked on the fish about 20 minutes later and one of the "catfish" had died.
The snail also hasn't moved since I put it in the tank (it was fine in the bag).
Please help! My tank temperature is ~25.5 degrees Celsius (77.9 degrees Fahrenheit). Am I doing something wrong? Thank you!