A necessity to removing the canister on the water filter.

The water filter housing will get firmly secured to the lid and you won't be able to easily unscrew it without this spanner. Some people might find it useful to have 2 of these to get better leverage but I am able to use only one just fine. The water filter lid must be mounted to a bracket that is attached to a board (get it at your hardware store) or you can mount a board directly on top of the lid. I took a 6x1/2 inch board and drilled out a hole for the vacuum release. I then screwed 2 inch screws into the four holes. This allows me to lay the canister on its side and get leverage from the board to remove the housing with the spanner.