Jestersix

Neptune DOS air in line

svreef

svreef

Webmaster
BOD
BARcard
I just reconnected my DOS using RO tubing directly into the input fitting. When I push and hold the priming button, I get no air in the lines. But, when it starts dosing automatically - it’s getting air in somewhere. It looks like it happens when it pauses. Any ideas?
 
Is this 1/4” ro tubing? I find that it’s pretty hard to shove that tubing on for a good seal. You really have to make sure you shove the ro tubing all the way as far as you can. Cup of hot water may help if you have trouble pushing it all the way to the end, then you really gotta screw it down tight. Also, if your ro tubing wall is too thin it won’t clamp down right. I think I read on the Neptune forums that if less than 1mm thick, the nut wont clamp down on the tubing enough.

If you’re set on using ro tubing, you may want to consider modifying the connectors to use 1/4” push adapters. The threading on the dos connector is 1/8” NPT so you could just buy a couple of 1/4” Push connect adapter to 1/8” NPT.

Here’s a reference for what needs to be done if you decide to go this route:

Neptune DOS Modification - Reef Central Online Community

Neptune DOS Modification Do It Yourself
www.reefcentral.com
 
I used the RO tubing as well but don’t recall any bubbles. I wasn’t using it for anything really important though either. I do remember having to jam something in the end of the tubing to open it up a little so it would fit on the dos. That mod that @RandyC referenced seems like a great idea I’ll have to try that.
 
I use RO tube as well and it’s been working well until this morning. It’s been introducing air and not holding any liquid for a week or so. I discovered a cracked tube at the DOS. Going to flare it with some heat today to see if it will last much longer.


Sent from my iPhone using Tapatalk
 
Over time, I have also had similar issues with Neptune specific tubing. I like the idea of switching over to RO tubing.
 
You must log in or register to reply here.
Back
Top