Can any rock be base rock?

[DoctorMatt]

So been lookin for some base rock that can be seeded by a few pounds of live rock but confused about what to buy. My Lfs sells several types of dry rock but wasn't sure if any rock can be used as base rock. They have this rock called holy rock that looks cool but don't wanna buy it if can't be seeded.

[ed102475]

I have used lace before.

[WaterKeeper]

Granite blocks are not too cool. You want something porus for de-nitrification. You can try pumice.

[jeff@zina.com]

You want calcerous rock. Basically, old coral skeletons. Beyond that, anything is fine. Stay away from any of the lava/pumice type rock (though it's often not an issue) and you're likely fine with what a normal LFS would have.

Jeff

[briankmarsh1980]

Granite blocks are not too cool. You want something porus for de-nitrification. You can try pumice.

doesn't pumice float? that would be interesting....

[Sk8r]

Avoid volcanic rock: metal content.
Stick to limestone, holey limestone. Dead coral is also very good.

[WaterKeeper]

As Sk8r points out, the reason pumice floats is that it is formed in volcanoes. You really don't want it in a SW tank as it leaches out all sorts of nasty by-products.

[MrGeoReefer]

Take some hydrochloric acid (hcl) with you to the fish store and drop a bit on the rocks, if they fizz then they can be used if not then no.

*you may have to scratch the surface of the rocks to get to a fresh part of the rock.

Good luck

[mykol]

Lawl @ hcl.