Black bugs? on live sand

I am kinda concerned about these very tiny black creatures on patches of my live sand. The are too tiny to take a picture of but when first looked at they look like tiny spots of some sort of algae, but apon closer examination I noticed that they moved and were shaped sorta like a very tiny black grain of rice.(hard to see with the naked eye let alone tell it was moving)
I don't know if I should be alarmed or not. Thanks for any input.
They seem to be more densely gathered on diatom patches that are left.
(Sorry I didn't see the sand section)

 

Do they have legs?

 

If I could magnify them I would be able to know myself
They are very tiny... think about the size of a period.

 

well I had a black unknown type of stomatella (half shell snail) just show up one day after my tank had been setup for 3 years, and now it has had babies apparently, there is a bunch of tiny bug looking dots in various places. I have a large table top magnifying glass that I use and thats how I knew what they were. If they are hovering around diatoms, then they are probally the good guys, so dont sweat it unless you see them on other things.

 

rosereef, I think it might be copepods. If its the size of a period, and you can see them move, i would think its a copepod. Those are good. The more you have, the better it is for your tank. Theres many fish that eat that as their primary diet. Search on this forum copepods, you gonna find a lot of info on them.

 

I have lots of them in certin spots where diatoms used to cover an area of sand. I never paid much attention till I looked closely and saw them move, wish I still had my mircoscope.
Fish appear to be fine, my mushroom coral cuttings are left alone, and plants growing great.....I suppose they aren't doing any harm I can tell.
Coraline seems to be growing quickly now too.

 

Sounds like your tank is progressing fast!!! I really do think those are copepods!! Its a very good thing to have them, dont worry bout them. They help the tank out a lot.

 

weird thing is at the present time I do not run a skimmer and I don't have a sump, yet my tank remains stable with the creatures living in it......prob helped that I added plants to the mix, I love the look.

 

Been there done that, 90+% they are pods of some sort.