Hi I recently started up a 90 gallon tank roughly 4 weeks ago. It has a 405 Fluval canister filter. When I go to remove the filter pads and clean them in water from the tank how do I do this? Do I just turn it off and open the top of the canister or will the water come out? Is there a way to pump the water out of the canister first before opening it? My tank sits on carpet and I dont want to drench it.