I recently upgraded to a 55 gallon tank. I used established media from my old tank and all the same bioload as I didn’t buy any new fish. In the tank there were 6 zebras and 2 fiveish cm Angels. One angel died in the old tank of unknown reasons took my water to the fish shop and they said it was all fine and was probably a bad fish the first angel became very weak and was turning upside down in the tank constantly until it died after about a day. Anyway fast forwarding to the new tank it’s been up for a couple of weeks now and has consistently had a concentration of around 0.25 ppm ammonia which I’ve been managing with prime and water changes every couple of days I guess the bacteria didn’t make it… almost a week ago my second angel died showing similar symptoms as the first but turning on its side and crashing to the bottom this time and that angel died in a day just like the other one. I’m trying to figure out what’s happened here? I’ve been managing ammonia with double doses of prime and the water the first fish died in was fine so what has caused this fish to die and could 0.25 ppm kill the other fish? I’ve also added dr timms one and only in the last day and nothing has changed with the ammonia as of yet does anyone know how long this process takes with dr timms?