My 55 gal broke out in an infection on my red eye tetras. I quarantined that group of species in a empty 10 gal. (My medical emergency tank) the 55 gal is doing good no other fish are showing symptoms. I am going to do a 20 or 30% water change when I wake up. It could be ich but who knows. I just dont want my prized koi bettas to get sick. Any tips on precautionary measures from longterm fish keepers?