Originally Posted by Maridia
I don't necessarily recommend this, but I use the black sand that you buy at petco. I bought for it's aesthetic quality. I think it's pretty sweet to have black sand and a painted blue background, then have your LEDs emit moonlight. It's tough to see algae, but still recognizable. But I don't think it has any of the beneficial properties like aragonite or crushed coral. I don't know if it's glass or died sand. Someone on here might know more about it's physical properties.
It depends on particle size. The bacterial lives on the surfaces, so it needs to be not too small so it packs together, but not too large as it looses surface area. It looks great to me as well, but I worried about silica particles. It doesn't have any chemical qualities of any kind that I am aware of.
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