Today I finished installing my Pure Freedom 450 RO with DI vessel in my garage. Ran water for 3 hours with flush valve open. Only leak was from screw in plug which hosepipe attaches to. More ptfe tape sorted that one. Here comes the good news, after turning flush valve off, and running a few litres, PPM read 003.(normal tap water for me is 105 PPM) Now to attach to DI vessel, and the bad news. I assumed that the rubber washer at top of vessel was enough to stop water leaks, fat chance, it pissed out. So I layered up the thread with more tape, lots better, just a small drip, so I'm going to try more tape and hope that sorts it. Can't help thinking the vessels could have a lot better seals to stop this problem?? Anyway I'm making 000PPM water, and have set the timer for filling my 500ltr holding tank. I'll let you know how long it takes. rs2315.