Help with live sand

[azndjay]

i have had my live sand for 3 months now . I only have 10lbs of live rock in my 44g coner tank. recently my tank has this black mold thing grow around it and its getting wider ...i need help on how to stop it and never having it again thanks

[BubbaWPB]

How do you know it is mold? Could it be a sponge?

[azndjay]

its not really mold i was useing it for example...its black and spreading along the bottom of my live rock ...some of the local lfs told me to scoop it out but it always comes back

[fish outa wata]

so is it slimey?

[azndjay]

yeah it smells last time i scoop it out of the water...now its turning brownish color , it happen about last week when i added a new lionfish...not sure if my lion are putting out outta waste that my filter cant handle it