Hi there i have a well established 260 litre tank. However i have been battling cloudy water recently. Now my clown loach has become ill with white spot. Its impossible to catch without massively desturbing the tank. I feel my best shot is to maintain the best water quality possible. I would like to know the max amount of water i can change and how often? I was thinking 20 to 30 percent a day for 5 days? Help please. Lol