Hello all, i bought a BHAF and went to install and ran into a small problem. I had a 4 1/8" copper pipe and i thought i could mount the filter minder and hook it all up. but it will not fit the new filter. I all so have a 4" PVC and it will not fit either. What do i need ? I tryed a search but no luck. Do i need a reducer PVC ? Thanks for your help guys.