Review on 💧 The Ultimate Pentek Big Blue Housing NPT: Top-rated Choice for Exceptional Filtration by Ronnie Polk

I love these housing blocks and have two of them but reassembly after changing the cartridge can be a little tricky. I have found that it is necessary to fully lubricate the o-ring and threads, otherwise the seal will go bad and there will be a lot of leaks after the water is turned back on. I think in our case there is a lot of iron in the water sticking to the o-ring and binding it when you screw the blue housing back into the top of the filter. If the O-ring is deformed, it will not seal well. The recommended silicone lube is expensive and hard to find. I've used petroleum jelly (less than $2 for a large jar at any pharmacy) with no problem. At least I didn't have to lubricate the first time since the o-ring was new and clean. But on two consecutive occasions when I tried to replace the filter cartridge and didn't bother to lubricate it, I found it very difficult to reseal it. Lubrication completely solves this problem.