I have a Kinetico K5 drinking water system and changing the filter is not too tough, except for the very last one. I cannot get my ham hands in the assembly far enough to get a decent grip on the front filter. So, after I finally got it out, I printed a wrench that you can reach in from the hole inthe bottom and engage the bottom of the filter. It is just a quarter turn, but when you only have wet finger tips “gripping” a smooth surface, it seems like 8 turns. This wrench greatly simplifies things. Print it with the handle up or down - you will need supports either way. I printed it handle up to waste less material and made it out of PETG. The inner support popped right out in one piece and the wrench fits perfect.
The author marked this model as their own original creation.