Help - Air getting into dosing lines on RedSea doser.

[anthonymckay]

Anyone else have an issue with air in the lines? I noticed that I had a ton of air in each of the lines on the outgoing ends of each pump, but none in the incoming side. I pushed each line firmly onto the pump and made sure it was tightened down really well, then primed each pum again to get all the air out, and within a couple days it looks like this again. It was the same thing it’s the colored Red Sea tubing as well, but you just can’t see the air bubbles since they aren’t opaque. Not sure how to solve this…

 

[colossal_tater]

What does the line into the dosing containers look like?

 

[JGT]

Had similar problem. Put check valves on all lines coming from dosing containers. Problem solved.

 

[anthonymckay]

What does the line into the dosing containers look like?

Connected to clear rigid tubing going into these dosing bottles these are daily trace elements and only dosing very small amounts each day (0.8ml) no air in the lines all the alway from the bottle to the pump. So certain the issue is something to do with the line connected to the output end of the pump

 

[anthonymckay]

It was suggested to me that the Red Sea dosing lines are NOT in fact silicon, but some other air resistant material. I switch both the intake and output dosing lines to the pump heads to Red Sea lines, and after a few days, I can see there are still bubbles in the lines (have to hold a light behind the lines to see it since they aren't see through).

 

[jimmypencil]

Ever figure this out?

 

[anthonymckay]

Ever figure this out?

Unfortunately no I switched the to OEM Red Sea dosing lines, and still getting bubbles. It's definitely happening at the head, because the line all the way from the bottle to the dosing pump is free of any bubbles. They only appear on the outgoing line of the pump. I've pushed the lines all the way on, and tightened them down as much as I can, but air still gets in somehow... I'm stumped.

 

[ryanjohn1]

Exit line in the water so there no chance it’s back feeding air?

 

[anthonymckay]

Exit line in the water so there no chance it’s back feeding air?

back feeding air all the way back to the pump head? That seems unlikely. You can see at the pump head where the lines connect bubbles forming at the connectors. It seems air just slowly permeates there each day, and then when the pump runs (each one is only dosing 0.75ml per day) it's moving those bubbles down into the outgoing line. You can see in the photos bubbles in the exit line spaced all the way down the line. That's my theory at least.

 

[ryanjohn1]

At one point if the hose end is not submerged the line to it will gravity feed what ever is in it down allowing the possibility of air getting in. I also had on one of mine pulling air at the connection from line to bottle and push fit connection at pump.