Had to wait on placement of the inside fills for these port and starboard tanks which go below bunks. I've water tested the Uniseal, which is only a couple bucks each, by sloshing water in the tank...time will tell. But folks use them commercially all the time so I have hope in my almost no pressure tanks. That's 1 1/2" PVC water pipe installed.

The installation went reasonably easy though I resorted to using a long clamp on my bench top to press it into the hole. I guess I was too wimpy to just wrassle it in.