DOS and DDR not priming

[BigTex1836]

I can get my 2 dos pumps primed when connected to another container. However when I connect to the DDR’s, I get zero fluid movement. Any ideas?

 

[Crabs McJones]

Did you double check that the lines were pushed all the way into the quick connect fittings on top of the DDR? I've done that before ;Facepalm

 

[BigTex1836]

I will check this evening

 

[Water Dog]

The 6mm OD flex hose that comes with the DOS is a poor match for the John Guest quick connect fittings on the DDR. It often does not seal properly to the JG quick connect fittings, hence the common issues with poor priming.

I am a big fan of this mod so you can use standard RO tubing with the DOS pump heads. It’s a serious head scratcher as to why they have two different connection types for the DOS vs the DDR. Here is a Neptune forums link to the John Guest fitting mod for the DOS. Follow the link in post #3 from the poster Wiretech who originally came up with this fix.

RO tubing to DOS connection

Hi, Has anyone seen an adapter that will connect standard 1/4" tubing used in RO applications to the larger tubing used on the DOS? Thanks, Dennis

forum.neptunesystems.com

If you do this mod, be sure to use Teflon paste (Plasto Joint Stik or Rectorseal) on the threads of the DOS nozzle threads for a leak free seal.

 

[ckalupa]

Also make sure those plastic tubes in the DDR are pushed up all the way making a good seal in the tank side. I had a couple where they were not seated.

The other thing I have noticed is some of the more viscous fluids (Red Sea alk) sometimes don’t like to come up that plastic tube. Either replace with a hose pc or switch alk.

 

[Evaaron]

The tubes inside the DDR should be glued into the fittings, if they move there is a >90% chance they will leak and cause the issue you are having. Neptune systems will warranty them if your DDR is less than a year old.

 

[BigTex1836]

The tubes inside the DDR should be glued into the fittings, if they move there is a >90% chance they will leak and cause the issue you are having. Neptune systems will warranty them if your DDR is less than a year old.

Thank you very much