Black Shiny Rock Type Thing In My Saltwater Tank?

Question

I have 2 (one very big, one just starting out) black shiny round things growing in my tank...one is growing on a rock and the other on soemthing else in my tank. They are hard like a rock. I am not sure what they are but I would like to know cause the one is getting rather large...and yes they are growing.

Answer 1

Is it slimy? It could be black algae.

Answer 2

black fungus,black algae or black mold.get a sea snail,they are bottom feeders and gobble it right up.

Answer 3

The only thing that is black and grows in fish tanks that I know of is black algae. I don't know if that's what's growing in your tank, but if it is you want to get rid of it before it spreads to other areas. Black algae can get nasty.

If only decorations or rocks are affected, it is fairly simple to get rid of it. Take them out and soak them in hydrogen peroxide (I have heard that bleach works too) overnight, then let them dry for at least 24 hours. The algae should just dry up and crumble off then. Make sure you rinse and dry the rocks/decorations thoroughly after that before putting them back into the tank.

Hope that helps!