question for seasoned keepers

was your product kalk also? or just a normal Ca salt suppliment?
kalk can do this:

Ca(OH)2 (aq) + CO2 (g) → CaCO3 (s) + H2O (l)
where Ca(OH)2 (aq) is what we look to put in our tanks. if the reaction has not gone to completion due to some lack of CO2, the CaCO3 (s) would stay present.
The molecule would be attracted to the semi-polarity of molecules in aragonite rocks and bind there, then the CO3 would be used as a carbon source (thus the biofilms)!

Fixes are: less kalk used in top off, OR vinegar added to kalk as a viable CO2 source to push rxn closer to the left...

Case closed! Excellent job Watson (jkat)

 

no kalk..I was only using liquid cal at the time..but way to break it down mister sci guy..lol great info..

 

update:
ok so its been 2 days with just plain rodi and no kalk. generally speaking, most parts look slightly less dense (but that may be due to me wanting them to be less dense lol) but it is still noticeably present.