u/LuanaEressea

Hi everyone, long time lurker, first time poster here. I tried cleaning my flower pots with citric acid to get rid of calcium deposits and limescale. One went finde, one got a little residue, and one got a lot. It disappears when wet and reappers when the pot dries. The bigger white spots on the bottom of the right one are leftover roots of my orchids that stuck to it, those are not the problem. What might it be and is there a way to get rid of it?

Both are the same mass produced ceramics as far as I know.