Is it good to clean the filters every once in a while. The whole thing.

woah! that's too long! i clean mine once every month.

It is always a good idea to clean the filter media about once a month. When you clean it though use the old tank water to clean it in as to keep the good bacteria alive. Try and clean the whole filter itself at least every other month as to not get a large algae buildup in the impeller and other areas of the filter. I have 3 different filters in my tank and I clean one every other week and that also seems to work well. I alternate though the filter I clean each week to allow the buildup of good bacteria.