Question: Help! White stuff in sand?

[Mxttbxrnes]

There's sorta white flakey things in my sand n Since I'm new to axolotls I'm seeing if I need to be worried? I worry about everything n just wanna make sure lil Caspar is okay! The tank has been cleaned recently so I'm thinking it could just be the sand?

I did attach an image (I think, I'm new to this site too!) so any response would be so appreciated!