Help with GHL2.1 doser issue

[VikS]

I bought a salve/master combo for doser 2.1 from a fellow reefer here. It was used for 2 years. Calibrated pumps and everything looked good. But out of 6 pumps in use, one of them dumped about 300ml of trace elements in my tank. I cant't get my head around how that happened. It was programmed to dose a few mls every other day. And the bottle did not drain completely. I tested the same pump and bottle by using the manual dosing button and it dosed perfectly. One thing that I should mention is that my bottles are at the same level as the doser (on the same shelf). So few questions:
1) Is it possible that issue is due to siphon? This seems to be the only possible reason why this issue would happen. But I thought that with these type of dosing pumps, siphoning is not a concern.
2) What kind of maintenance/replacement should I do on these pumps to renew them.
3) One of the pumps is not sucking any liquid even though the pump rotates. Any ideas on what to do. Replacement tubing?
4) Finally, I can't get it to connect to GHL cloud service. I can use the GHL connect app as long as I am on the same network. Any resources that I can read up on to figure out the issue.

Thanks you!
V

 

[hotdrop]

Is your container located above the exit point of the doser? If so it will syphon if there isn’t a perfect seal at the doser head. You can check if that’s the case by simply fixing the arrangement and checking to see one of the tubes drains back into the container

 

[chefjpaul]

Can you post a screenshot of the settings?

They don't back syphon in normal conditions.
Check for air leaks?

Also- 2 years, used. I suggest getting new heads & tube, Never know how many miles are on them. That's quite a bit of time.

 

[VikS]

Can you post a screenshot of the settings?

Had to overwrite the dosing setting to turn auto dosing off. So screenshot will not be helpful. Its interesting that the tracker on the doser still shows bottle 90% full, so I think settings are fine.

Is your container located above the exit point of the doser?

I checked that the siphon stopped when liquid level in bottle fell below the doser exit point. So it all makes sense.

I will replace the tubings and head for sure. thank you!

 

[AZMSGT]

Had to overwrite the dosing setting to turn auto dosing off. So screenshot will not be helpful. Its interesting that the tracker on the doser still shows bottle 90% full, so I think settings are fine.

I will replace the tubings and head for sure. thank you!

just an FYI, you can buy the tubing and cut to length, also the rollers and blue cover can be bought separate. It’s cheaper than buying the entire head assembly.

 

[Vinny@GHLUSA]

Given the age of the unit and being bought second-hand, it would be tough to find out how often (if at all) the pump heads and tube were serviced. At 2 years, they should have been replaced at least once otherwise you may run into dosing consistency issues.

I suggest getting 4x complete dosing pump heads for the D2.1.
That comes with everything you need for a fresh start.

 

[hotdrop]

I suggest getting 4x complete dosing pump heads for the D2.1.

After you factor the cost of those in suddenly a used doser costs exactly the same as a new one

 

[VikS]

After you factor the cost of those in suddenly a used doser costs exactly the same as a new one

Very true. I did not factor that cost of heads but the units were cheap. So I am still 200$ ahead.