Originally Posted by
ksuyen
I would say it's both. I will let the others with more knowledge to explain. Discus is an expensive fish, it's a better prevention by doing frequent WC before anything happens. There are a lot of factors involved: fish age, aquarium size, equipment, dosing, breed, planted vs bare, etc. Generally people has more success keeping discus for longer time with frequent wc compare to those with less. In my opinion, keep your water clean, keep varied high quality food, etc. and not worrying every little things are essential. Just my 2c.