Yes, you can do it that way. But most of us only change around 50% weekly, and only 90% if something has got into the tank that shouldn't be there such as someone dumping a whole can of fish food in the tank, or painting in the same room and the paint fumes distressing the fish.
Most of the biofilm is on surfaces such as every bubble in a filter sponge. Yes, the brown sludge does have bacteria etc in it, but it can also be washed off regularly without affecting the tank. One of the things the brown sludge does is stop water flowing through the filter, which the bacteria etc need to thrive.
Most of the biofilm is on surfaces such as every bubble in a filter sponge. Yes, the brown sludge does have bacteria etc in it, but it can also be washed off regularly without affecting the tank. One of the things the brown sludge does is stop water flowing through the filter, which the bacteria etc need to thrive.
did a 50% water change today and I'll continue on. I quite enjoy water changes so no issue for me. Just need to find a strong pump to pump in and out through a long tube from tank to garden and from bucke inside bathtub to tank. Make it easier. If you know a good submersible pump brand that could manage that.. Do suggest. Else, thanks a lot for info 
