lava rock

[raoul]

I got a cool piece of black lava rock from a local landscape supply yard. It is currently in my cycling tank. Last night, while reading in another forum, I came across a post that indicated that some types of lava rock are not reef-safe. Does anyone have an opinion on this they will share?

thanks

 

[OrionGirl]

Most lava rock is not really lava (as in from a volcano), but rather is a by-product of metal processing. As such, it's usually inert. I've had red and black lava in my SW tanks with no problems. Just test your water parameters to make sure it doesn't negatively impact pH and alkalinity, and watch for any discoloration.