Lava rock in refugium

[aquablizz]

Has anyone ever used Lava rock in an refugium.. seems like it would be a perfect medium and very cheap..

blizz

 

[FarmerTy]

I know nothing of lava rock composition but I would imagine its high in metals considering its origin. If that's the case, using it in an enclosed saltwater environment would be a terrible idea.

 

[aquablizz]

never thought about the metal aspect... I just know it is very porous.. have seen it in fresh water applications but just for decorations. Also have seen different colors of this rock gray, black, and reddish brown which I would suspect might contain high levels of iron.