Drew Shark
Community Member
I am attempting to get an AWC system set up for my 200 gallon system. The lone snag is that my DOS leaks. It is modified with John Guest push connect fittings. However it appears to only be on the "out" side. And only leaks when it is connected to the 50 foot section of hose. I tested it with a 10 foot push. That is no problem, no leak.
I have my saltwater reservoir outside. it is about a 50 foot run of 1/4" RO tubing away from the tank. Flat ground. Single story house. Goes through the wall about 1 foot above ground level. So no "head pressure". But a lot of resistance from the RO tubing.
The DOS is located in the water change shed. It can suction from the tank 50' to a bucket. No leaks. However, the NSW side pushing 50' to the tank leaks a drip per head revolution. No good.
The leak appears to be from above the John Guest push connect fitting. Like inside the peristaltic head itself. I am wondering if the pressure is so much that the little zip tie that holds the peristaltic tube to the grey plastic fitting is not strong/ tight enough?
For the push connect modification: I sawed off the nipple on the DOS head. Used Rector seal PTFE teflon paste. A fairly good couple dabs. Screwed on the John Guest fittings.
And by the way, all parts are brand new, never used until this. So there should be no wear etc.
I am at my wits end with this DOS. I am looking at just going Stenner Dual head. Or Masterflex. I have been in the hobby for over a decade and done a lot of plumbing. However, this is really perplexing.
To me it seems as though the DOS cannot do this much head pressure. Has anyone do this long of a run or more? And how?
I have my saltwater reservoir outside. it is about a 50 foot run of 1/4" RO tubing away from the tank. Flat ground. Single story house. Goes through the wall about 1 foot above ground level. So no "head pressure". But a lot of resistance from the RO tubing.
The DOS is located in the water change shed. It can suction from the tank 50' to a bucket. No leaks. However, the NSW side pushing 50' to the tank leaks a drip per head revolution. No good.
The leak appears to be from above the John Guest push connect fitting. Like inside the peristaltic head itself. I am wondering if the pressure is so much that the little zip tie that holds the peristaltic tube to the grey plastic fitting is not strong/ tight enough?
For the push connect modification: I sawed off the nipple on the DOS head. Used Rector seal PTFE teflon paste. A fairly good couple dabs. Screwed on the John Guest fittings.
And by the way, all parts are brand new, never used until this. So there should be no wear etc.
I am at my wits end with this DOS. I am looking at just going Stenner Dual head. Or Masterflex. I have been in the hobby for over a decade and done a lot of plumbing. However, this is really perplexing.
To me it seems as though the DOS cannot do this much head pressure. Has anyone do this long of a run or more? And how?
