Putting Kalk in the ATO?

[SteveConn]

I've been running kalk/vinegar diluted in RODI water for about 3 weeks thru my Tunze ATO.. levels are good as long as I dont run a cooling fan (levels shot up), however, my pump doesn't sound normal...noisy now when it tops up. I think there is calcium buildup in it. Was thinking of running straight vinegar thru it to clean it out.
The Kalk/vinegar method can be found online.

Debating going to 2 part dosing or just getting a Calcium reactor as I already have the CO2 tank, solenoid and ph monitor from a planted freshwater setup I used to have