Does this Red Slate look aquarium safe?

[AshK]

So I purchased some red slate for hardscape in my tanks. Some of the pieces have weird rust-looking spots on them. I boiled all the pieces, and I'm wondering if they are safe or not!http://i85.photobucket.com/albums/k75/bravecaspian/Photo419.jpg

http://i85.photobucket.com/albums/k75/bravecaspian/Photo416.jpg

(Sorry about the crappy photos, I used my webcam)

[Ozymandias]

try adding some vinigur to it if it bubbles it's not safe for you're tank. there are also some other acids that do the same thing but more affective but i cant remember there names.

[AshK]

dang nab it! I used the vinegar trick and the freaking stuff fizzles like crazy! What is the deal? I read stuff online saying it was aquarium safe (and saw no opposition)!!!:mad2:

[jm1212]

slate should be inert...

[Riiz]

There could be iron in your slate. Idk, you could try the bucket test, soak it overnight or for a couple of days and see if changes the water chemistry.

[AshK]

http://www.youtube.com/watch?v=0Gq1tEbPyvM
http://www.youtube.com/watch?v=0Gq1tEbPyvM

Here's a video of it when I put it in white vinegar. You can see the vinegar becomes almost a suspension with fine little red dust in it. Does this mean it is 100% unsafe, or can I do the bucket test? What sorts of things should I test it for (do I need to test it ammonia, nitrites and nitrates, or other things like PH and hardness?)

Thanks guys for all your help!

[247Plants]

I wouldnt risk it......