New member
Hi, I have just started dosing kalk (today) with my RO/DI topoff water and Osmolator 3155 and noticed that when the pump starts it seems to 'struggle' pumping, instead of making its normal whirring sound it seemed to be a lot slower than normal, is this ok. It does pump but seems to make a different sound, is this ok? My plan was to see if Kalk would keep my levels of Cal/Alk stable (over a couple of weeks) and then to buy the Tunze calcium dispenser for dosing it.

Any advice appreiciated.

You may want to lift the pump off the bottom of the container so that is is not pumping insoluble kalk. I guess that could be the problem.
Hi Roger
No, the pump does not seem to be pumping less (pump is about 12 months old), just makes a different noise now, not it's usual fast whirring sound, seems to be a slow deep whirring now I have kalk in the water, Just wondering if it will be ok. As stated, if the cal/alk stay stable in a week or so I will buy the calcium dispenser. The pump is approx 3" from the bottom.

That sounds normal, when new they do make a sharper noise that mellows a bit with use.