Kalkwasser stirrer

[Madreefer]

I had the same problem, I put a one way check valve on the fresh water supply line. Problem fixed.

[Skimmerking]

i have been running my Kalk Stirrer the Barr Aquatics K3020 from the RO/DI and all you do is run the line and before going in add a small Gate Valve to the input so you only let in what you are turning.
ie if you want 1 drip per sec going in then 1 drip per sec is going to come out. its fool proof I have been running this setup for atleast 10 years