What is in my sand ?

[Aloha919]

I noticed this black stuff in the sand of my tank. (See photos) . It may be old food. I dropped a small bit of shrimp food as a treat for my guys. They swarmed and ate most of it, I later siphoned the leftovers. Could this be old food that settled ? It's just strange, any input would be appreciated. The shrimp are doing fine otherwise.
Thanks in advance

[Stalker]

It's autotroph bacteria, nothing to fear.

[Mustafa]

Do you have snails? In tanks with burrowing snails you have less or none of that going on. Also, I wouldn't siphon the food. It just disturbs the tank. Just feed enough so that it's gone after a few hours.

[Aloha919]

Thank you so much
I've been wanting to get some snails, but my pet store did not have the ones I need. I know mystery snails can't live in brackish water can nerite snails ?

[Munakgirl]

Try either the snails that are on this website. Or see if your local petstores have 'trumpet' snails. Sometimes stores don't 'sell' them because they ate just considered pest snails in most tanks cuz they feed and gets over populated. But sometimes you can get them for free... my local petsmart just gave me some cuz they have a hard time getting rid of them. ^^;

I slowly aclimated them to brackish water over a few days. Since unlike mustafa snails they won't be used to brackish water right away.

An you could get a nerite snail, but they eat a lot more then trumpets, and they do not burrow. So it's prefered to go with a few burrowing snails if your having the problems in your sand.