Help Someone Please!

[rocknurworld2006]

Hi i have a 5foot tank with sand as the substrate and at the front below the top level of sand , basically inbetween the bttom of the tank and th top of the sand i can see some black stuff, can anybody tell me what this is and how to get rid of it?,

i am worried that it could be hydrogen sulfide gas producing

 

[SJ2K]

Yup sounds like a dead spot, im no expert but im fairly sure these things are exaggerated a little, ive never heard any stories of this gay causing harm to fish If your going to use sand as a substrate its a good idea to 1) Use plenty of live plants 2) Buy yourself some malaysian trumpet snails which constantly turn over the sand this should help prevent this in future, for now im sure it'd be ok to just stir it up yourself to release any build up.

 

[PrettyLittleLamb]

The best thing you can do now is turn the sand over so the 'black' bit is exposed, within a day or two it'll fade back to the original sandy colour. After that make sure you keep on top of turning it over ESPECIALLY under rocks/decor