u/wikstaa

Hi! I’ve had them for 3 years, and recently I noticed this weird white coating on them. It looks almost like tiny grains of sand or dust stuck to the surface, but it’s definitely not actual sand. They sit on stones in filtered tap water.

I’m wondering if it could be another type of algae, fungus or maybe mineral buildup from the water? They still feel firm and mostly look healthy otherwise, and they don’t have any smell.
I try to change the water regularly and keep them in a bright room, but never in direct sunlight. When I clean them, I rinse them under running tap water.

Has anyone seen something like this before? Any idea what it could be or how to treat it?😅