I thought that dinoflaggellates but now not sure

I thought it dino but when I put it in glass it moves. It cover like brown carpet sand and gone for night time, than in photoperiod come back. Is it algae, bacteria or kind of warms? By the end of day I can see bubbles on rock and sand close to this

 

Those are unfortunately Flatworms.

The link below will start you on your research of the problem.

Melevsreef.com - Flatworms | How to eliminate them!

A word of caution, if you decide on Flatworm exist you will need to extensively remove as many as possible. FW release a toxin upon death that will kill your live stock. What you see is a small percentage of the population.

 

Tnx for quick peplay)) will do now right thing