Versa dosing pump calibration questions

[ThaBeast]

I use Versa dosing pumps for my AWC. I just calibrated the New Saltwater pump last week. Seemed like my ATO was running too much so I checked calibration, it was off by 30%+. My storage container is only 25% full and 45 ft away. Did the level of the storage tank affect my calibration? I find it disheartening that calibration drifted that much in a week

 

[CasperOe]

I wouldn't think so, the versa is a very capable pump indeed. You have no head /suction pressure to worry about with this kind of dosing pump.

It's a long line, did you make sure it was fully purged? Air in the dosing line will affect your calibration.

Also, check all your fittings (if you have any!)

 

[ThaBeast]

I wouldn't think so, the versa is a very capable pump indeed. You have no head /suction pressure to worry about with this kind of dosing pump.

It's a long line, did you make sure it was fully purged? Air in the dosing line will affect your calibration.

Also, check all your fittings (if you have any!)

Thanks I didnt think so either. Only fittings are on the versa pump itself. Perhaps there was an air pocket stuck in the suction line when I calibrated last week. I did inadvertently turn the mixing pump on so it is possible the suction line picked up some air, I had forgotten about that incident until you mentioned air in the line

 

[JHSteepat]

I had a very significant difference once set up and pre-calibration between the fill and drain pumps, but I am pushing and draining 10-12 feet vertically from my basement. I think I was ~20% off in both cases, in the direction I would have expected pushing water uphill vs controlling the siphon to the basement sink drain.

With respect to air in the line, I needed to purge the lines with RODI for about a liter before calibrating with a 1L graduated cylinder (500mL). Total run is about 25 feet between basement and tank. Pumps are in the basement.