Slate & Sandstone in a salt water tank

[hrdneglcry]

A LFS recommended that I not use slate in my salt water aquarium which is fine with me, but I do like to use sandstone, and I am wondering if anybody knows if there is a reason that I should not use sandstone in my salt water tank.

[BubbaWPB]

Many of the land-based rocks have contaminating heavy metals in them. I'd stick to cultured or natural live rock, cured aragacrete, or ceramics created especially for use in saltwater.

[hrdneglcry]

This sandstone that I am using is pure white. It is 2.5 inches thick. What can happen with the metals?

[BubbaWPB]

The metals are toxic to tank inhabitants, especially invertebrates. Color may not be a good indication... many heavy metal salts are white (lead and barium are two I can think of off the top of my head).

[smidoid]

I tend to think that if I didn't come from a reef, then it's best avoided unless someone knows better. As Bubba says, Aragonite or Argocrete are the best things to use. The only rock in my tank was "harvested" from the same type of seas that my fish come from.

[hrdneglcry]

OK. What about Holey Rock? The LFS uses it.

[Ninong]

OK. What about Holey Rock? The LFS uses it.

Do they use it in reef tanks or just African cichlid tanks?

The potential risk when using limestone is that you never know what impurities it may contain. Clean, pure limestone obviously doesn't present a problem but in checking this vendor's description of their Texas holey rock, I can't help but wonder when they caution that their product may require some additional cleaning before using in your African Rift Lake tank.

Inland limestone is quarried for use as aquacultured live rock in Florida. That's why it's so dense. And there is an outfit that digs this stuff up in Haiti. The product from Haiti has lots of holes in it, similar to the Texas holey rock.

Even though limestone is nothing more than ancient coral reefs, you never know how many times the crust has been folded and turned in the millions of years since it was laid down. You could have some feldspathic veins running through it and this could cause elevated silicate levels in your tank. If you decide to use it, inspect it carefully before purchasing it.

[gregb]

There is nothing like the taste, smell & expense of real LR.