Hi
IME the carbonates will disolve in the RO water given enough time.Rubbing it will also hasten the disolving.
Check your water hardness and see if the pH is high enough to cause precipatation. any thing above 7.
Change the water as it disolves and replace with RO water.
gary

I use white wine vinegar myself. It will remove absolutely any deposit from glass. I've never used it on an amphibian tank that had animals in it at the time, so you might want to ask someone who knows more about them if it is safe. But I use it on my cage any time it needs it. Just put a bit on a soft cloth and wipe the surface of the glass. I usually go back over it after that with a dry cloth to remove anything that is left.

-DH

Cool, Thankk you both for the advice =)

Vinegar will do the trick. It's non-toxic, so it shouldn't hurt the animals, but it is still an acid, so just to be safe, use only a very little bit, and clean it off with an RO water rinse afterwards. Lemon juice would also work in the same way.

I work at a zoo and we use slightly diluted white vinegar to remove the calcium stains from our dart frog tank. We spray the dilute vinegar on a paper towel and then simply rub the glass to get the stains off. Follow up with a dry paper towel to remove any residue. For particularly heavy stains which we get from daily spraying in some off exhibit enclosures we use a razor blade to scrape the residue off and then follow up with the usual dilute vinegar and dry paper towel.