This is highly aerated portland cement and is 100% reef safe. I bought a bunch for a tank I was working on and this is what is left. Large formation in the back (4 pieces total) $90, back right $15, back left $30, middle formation (3 pieces total) $40, front right formation (3 pieces total) $35 or take all for $180. 16 oz glass for size reference. Multi piece formations are loose and come with epoxy and cement crumbles to cover epoxy. Scape your entire tank for a fraction of the cost of heavy liverock. Message with what pieces you want after requesting please.
What You See Is What You Get Ultra Rainbow Acan. Gown under LED/T5 20k spectrum combo for over 4 years. This will color up even better if you have bluer lighting. This was stung a few weeks ago by a frogspawn that fell over but as you can see its coming back already.