It is the best thing in the world. I have had Lava Rock in my tanks for 5 years and will never put anything else in. We have lava beds around here and my wife and I make yearly trips. The rock is very porous and with time it gets filled with good bateria and becomes "live rock." Provides great filtration and it stacks really well. Many get concerned about the sharp edges, but the fish don't seem to have any problems with the rock.
If you get the chance to get some do it. Look for the following qualities, is it the black porous kind. Some try and pass off red man made stuff as lava rock. Is it heavy enough to sink and stay put on the bottom of the tank, but not so heavy that it is a pain to remove it if necessary. How big are the holes in the rock? The more holes, the newer the Lava rock. Older rock will be smoother, with less surface holes, and will be grayer looking.
Hope this helps.
If you get the chance to get some do it. Look for the following qualities, is it the black porous kind. Some try and pass off red man made stuff as lava rock. Is it heavy enough to sink and stay put on the bottom of the tank, but not so heavy that it is a pain to remove it if necessary. How big are the holes in the rock? The more holes, the newer the Lava rock. Older rock will be smoother, with less surface holes, and will be grayer looking.
Hope this helps.
