I have around 75-100 pounds of worm rock. This rock is a limestone base and is out of the kimmswick formation in st. louis. I am looking to unload this stuff cheap because I bought an excessive amount and have no other need for it. I will post pictures of this rock if anyone is interested. I used it for my cichlid tank. The rock is free of metals, impurities ( I am good friends with the missouri dept. of transportation geologist that tests this formation). It would also make good live rock. Let me know if anyone is interested. I have varying sizes, weights.