Midwest Hearth – Extra Large Natural Tumbled Lava Stones for Gas Fire Pits | 10 lbs | Smooth Round Volcanic Rock (3″–5″)

I didn’t want to spend the money for these lava rocks. You can get your typical red jagged lava rock pretty cheap, but I generally don’t find this color, size, or shape locally. So I went ahead and spent the money, and happy I did. These rocks look fantastic in the fish tank, especially against a light sand substrate. Added bonus is that the pours promote the growth of beneficial bacteria. They do come out of the bag extremely dusty and look much lighter. I gave them a quick rinse in tap water and put them right in the tank.