Piece of Mt. Vesuvius in my tank?

[cigs4kids]

I've just gotten my hands on a little hunk of pumice or lavarock or something of that nature (that originally came from Mt. Vesuvius). Anyone know if this would be safe to put in my tank? How would it affect the water chemisty? How should I clean it beforehand?

Any advice would help.

Keith

[OrionGirl]

Give the vinegar test. Bubbles mean it will affect your chemistry, no bubbles means it might not. Best way to check is to put it in a bucket with some water from your tank, let it sit a week, and then test the pH, GH and KH (assuming that you test these value before adding the rock as well! ;) ). If there's a huge change, I wouldn't add it.

[mogurnda]

You might also want to consider heavy metals. A lot of volcanic rock contains arsenic and other nasty elements. No way I can think of to test, without spending way too much money. For a FW tank, I'd toss the stuff in if it passes the fizz test, but keep it in mind if your fish start acting funny.