Lava rock

I bought my tank used and I have a good one piece (10lb) lava rock that is used as a cave because it has big holes and tunnels. It was bought by the previous owner at there pet store and used it as part of her live rock collection. The question is I thought I read somewhere that lava rock was a bad thing for a saltwater tank. Just wondering. It is growing Macro on it but nobody wants to eat or pick at it. Any thoughts?

ADD ON: Sorry forgot to add the part where it is growing alot of macro (green) on it at this time, but oddly enough the sea urchin, snails, starfish and other macro eaters like a lemon peel don't really mess with it or eat the macro on it. Also would this rock be a possibility of why I can't get my Nitrate down? I understand what Nitrate is but just wondering of the possiblilty.

 

i once killed all my fish with lava rock that elmers aquarium in monroeville pa told me would be safe in my sw tank.

 

Lava rock is not a good choice for a saltwater tank IMO!
I would get rid of it and get some other form of live rock as their is so many nice choices to choose from, such as Tonga, Fiji and Marshall Island.

 

if you don't want live rock,you can get tuffa rock thats very porous and has caves carved in it rather than lava rock.tuffa will even perform some filtration.some nitrates will be consumed in its pours.live rock does it better though.good luck.

 

All rock will become alive with in a few months as for lava rock god only knows what all metals and mineral are in the rock Iron copper zinc silver ???? and many many more after all it was magma from the earths core when it came up for air never use that stuff