sand turning black

[catchndolphn]

I added live sand to my tank a few days ago, its actually been about a week now, and i noticed towards the bottom of the sand bed the sand is turning black. is this ok? the tank is still in cycling.

 

[dskidmore]

What method are you using to cycle the tank?

Where did you get the live sand from?

I would suspect that the sand bed is deep enough that the bottom layers are not getting oxygen, and some of the things previously living in the sand died down there. After you finish cycling, you can get some critters that like digging in the sand, and they'll keep it nice and healthy for you in the long run.

 

[CMD26]

It could just be diatoms which are normal.

 

[dskidmore]

I thought diatoms were usually on top of the sand? There's still so much for me to learn in this hobby.

 

[cmor1701d]

Diatoms are on the top of the sand bed. Sand turning black is on the bottom is a sign of a build up of sulphur dioxide. Large areas can be toxic to the tank if disturbed. I'm not sure this would happen in a week's time, so maybe something else is going here. If the tank is still cycling and there is no livestock in there I would disturb the sand bed where it is black. Use a long wooden spoon or a net handle, etc. to mix up the sand in that area. If you get a rotten egg smell then it was a sulfur dioxide build up.

How deep is your sand bed now?
What was your substrate before you added the LS?