Regarding some rocks

[james00]

I saw these "crystal white rocks" and I am wondering if these rocks have any potential harm or any helpful contents in it? I searched on google but I have found nothing. Thanks in advance

 

[sumphead]

Nope. While not knowing the rocket science of it all it is my understanding that these rocks are sodium based and will slowly dissolve over time. I have heard there are more than one type if these "ICE" rocks and some are good but I would never recommend anything but aragonite/calcium based rocks in a saltwater tank. Even in fish only tanks it is important to use natural occuring substrates and rocks. Not only will they help buffer pH and calcium levles they look more realistic. Not to forget rocks not naturaly found in saltwater run the risk of leeching unwanted substances and even if thought to be inert may have a nutralizing effect on pH. Stick with the good stuff.

HTH,
R-