Has anyone tried this in their vivs, I just bought a pack of 6 bricks, and am wondering if it's ok for frogs to come into contact with. It's Styrofoam Brand Gentle Grip Standard thir site is http://www.styrofoamcrafts.com , I think it's just green styrofoam, but I'm not positive. I was planning on using it in place of gravel on one tank just to test it out, gravel, screen, substrate. But I can't find anything about what it is exactly unless it is just styrofoam. Any opinions would be welcome. I'd also be curious as to what people thought of partially hollowing it for live plants so they can be planted deeper os sloping it and having a water feature. It does float and has a powdery sand texture to it.