Doser keeps pumping air into tubes

[scotty333]

Guys, I have 2 Jebao 4.4 dosers and 2 channels on 1 and 1 channel on the other daily get air in the tube
I’ve tried everything! Gluing and taping the tube inlets , squeezing the tube at the inlet in case there’s a bubble and everything else I can think of.
My lfs tells me they sell tons of these with no negative feedback so what am I doing wrong?

 

[Doctorgori]

if air is getting in somewhere it’s gotta be in the line as I thought dosers simply “squeezed” the liquid along vs pumping it directly
…., so any air in the line is either entering at the container or it’s in the tube
….have you inspected or changed the tubing?

..I’ve owned Jebao dosers before, several …so while Jebao isn’t a top shelf brand I’m hesitant to blame this on the doser per se

 

[Cell]

Must be a leak somewhere. The next step would be swapping out the tubing if you are able.

 

[scotty333]

The tubes in the bottles are air free as are the outlet tubes when I run it through but at some point during the daily 20ml dose it’s getting about 5ml of air in the outlet so I’m at a loss where it’s getting it from

 

[scotty333]

if air is getting in somewhere it’s gotta be in the line as I thought dosers simply “squeezed” the liquid along vs pumping it directly
…., so any air in the line is either entering at the container or it’s in the tube
….have you inspected or changed the tubing?

..I’ve owned Jebao dosers before, several …so while Jebao isn’t a top shelf brand I’m hesitant to blame this on the doser per se

Also, the tubing is all good and even if there was a pinhole it wouldn’t suck air. Through as the liquid would “ seal” it

 

[Solo McReefer]

A leak in the peristaltic tubing? The part the little wheels smooth to force the fluid through

I would replace that, and the fittings first

Even if new

Could be a bad-out-of-box tube

That can happen on any brand of peristaltic pump

 

[scotty333]

Must be a leak somewhere. The next step would be swapping out the tubing if you are able.

I’ve got 40m of tubing arriving imminently so I can put 20m on each kh solution which buys me 10 days of worry free

 

[scotty333]

A leak in the peristaltic tubing? The part the little wheels smooth to force the fluid through

I would replace that, and the fittings first

Even if new

Could be a bad-out-of-box tube

That can happen on any brand of peristaltic pump

Makes sense since it’s not all 8 channels

 

[Garf]

Makes sense since it’s not all 8 channels

You got bright lights, or something heating the tubing? You got one way valves fitted?

 

[scotty333]

You got bright lights, or something heating the tubing? You got one way valves fitted?

Dosers and tubing above the light so no strong light
The valves is something I hadn’t thought about but would certainly rule out “back pressure “
I’ll get some on Monday to try out
Thanks , that could be it!

 

[Dburr1014]

Have you checked you check valves?
Nvm, you got this!

 

[scotty333]

Have you checked you check valves?
Nvm, you got this!

Check valves?
What’s nvm?

 

[Dburr1014]

Check valves?
What’s nvm?

Check valves should be on the lines. It prevents air coming in or back feeding.

Nvm = nevermind

 

[Jamie814]

Check valves should be on the lines. It prevents air coming in or back feeding.

Peristaltic pumps should not need check valves. If they do, they are not working properly or the tubing in the pump is too small.

 

[Solo McReefer]

Peristaltic pumps should not need check valves. If they do, they are not working properly or the tubing in the pump is too small.

In theory

This is true

 

[Dburr1014]

Peristaltic pumps should not need check valves. If they do, they are not working properly or the tubing in the pump is too small.

Yes, true. I agree.
But if there is an air leak, it helps.

 

[scotty333]

Nevertheless I’ll try them on Monday , otherwise I’m stumped and will return it

 

[scotty333]

What a day!
Was doing the daily “ run out the air in the tubes “ and forgot to take them out the tank into a cup so dosed like 7-8ml into the sump , reading an hour later 8.7 from 7.9 before the c0ck up

Think I got away with unless acros take a while to let you know?

Then because I’m wasting so much solution I had to put new on but the solution would dissolve so had to go back to lfs and get another

Just hope the concentration is the same or it’ll be another mess in the morning

 

[Solo McReefer]

.

 

[scotty333]

I'm still dosing via water changes

Hard to screw that up

Maybe try that, or not. Up to you

With 2.5 dkh consumption a day I’d be hard pushed keeping that maintained with water changes but keep doing what suits you , all the best