Our shower massage was leaking where it coupled to the supply pipe. OK, it's been there a few years. So we were at Costco yesterday and I picked up a Waterpik unit. Fihured it'd slide right in no prolemo. Yeah. I got the thing in, using their .5 point type instructions, turned it on, and guess what - it leaked at the coupling. Took it apart and redid everything, 6 times, and got the same thing every time. Finally, before taking it back, I removed the "filter screen", which I think is actually a pressure reducer, and not only does it no longer leak at the coupling, but I have better pressure in the shower. I looked and the old unit has a "filter screen", too. Is this an EPA mandated way to ruin my life? There is NO WAY this thing would work with that POS in there. The pressure behind it was too high. I couldn't tighten it down tight enough to get a seal. Any ideas, GT plumbers? Thanks!