I have to re-do the plumbing going into the ultima since that's where theres' a leak. I used plumbers tape, but either not enough or I might use silicone in the thread as well.[/quote]
Yep, you will have to use clear silicome to seal the ultima filters. I had one and I used tape and even the teflon paste and it still leaked. Took it back and got a brand new one only to have the same problem. For some reason the three fittings that screw into the ultima leak badly. I just put clear aquarium silicone sealant on the threads and screwed them in and they were as dry as a bone.