About a year ago someone gave me this kind of rock because his aquarium broke. I never had the chance to ask him where did he get this from, but anyways I put it in my tank then and I lost 2 goldfish because they got stuck in it's holes
... Since then I removed the stone and it's still in my room as a decoration. I got swordtails now, because I realised that I didn't have a big enough tank to keep goldfish, and I bought sand and I'm planning to aquascape soon. But I took a look at the stone today and I'm considering to put it in my tank, I'm just not very sure if it can be sure for my swordtails, I'm affraid of losing other fish. but it has A LOT of holes as hiding spots for my fry
Anyways, can it be a coral? There are no coral reefs here in Albania and I don't know anything about corals, so I cant be sure. What I know for sure is that this is a 100% natural stone/coral whatever, I mean it's not fake. It has some kind of crystals, just like salt crystals on it, so I think that maybe it might raise my pH?
Anyways, I'm attaching a picture, would be very grateful if you could help me