Adding a filter to established tank
So I'm wanting to buy a canister filter for my established 40 gallon. The tank has been running for around 3 months, has 2 internal filters and a hang on the back filtre already in it and has 6 African cichlids in it. But the filters are still not keeping up and the tank gets cloudy and dirty after after a day. i do w/c 2 times a week.
I was wondering how I would go about adding the new filter. Do I have to remove the fish or can I keep them in?
I am planning on taking the two internal filters out eventually.
Thanks for your help