Cloud Shape Things In Sand?

[Dreamer03]

First all my fish died from some weird thing that I still can't figure exactly what it was and now there is cloudlike things forming in the sand. What is this and is it something I should be concerned about? Let me post a picture....

 

[starlitsunrise]

Ok this is just a guess, but I just thought that maybe this could be gas build up that is escaping the sand? Do you periodically move the sand around to let the gas escape? I really don't know if this is what it is, but it is the first thing that popped into my head. Hopefully someone with more experience will be able to help. 

 

[Dreamer03]

Yeah i do but that couldexplain it...

 

[Donya]

Hard to tell from the pictures. Bacterial blooms can cause films and/or globs of mucous-like stuff to form quite fast on various surfaces.