quarantine therapy

Hello everyone, I'm trying to organize my first quarantine setup and with my research, I think I've come up with the following process: Part 1: run API General Cure go by the directions on the bottle, but do the 20-25% water change after 4 days Repeat dosage then 4 days later do another 20%...

I keep losing my fish in qt. Treatment is Cupramine and sometimes PraziPro. I don't use Prazi but once a week if I use it. My fish will be fine for a week and then they just crash. Ammonia not 0 but .05-.25. Ph is 8.2. Salt 1.026

So I was doing a tank transfer and To my surprise I noticed my Ecotech Radion xr30w pro g4 light went for a swim. Any advice or similar experiences?