I was looking for cuttlebone in a pet shop a few days ago but they weren't selling any and gave me an alternative, a mineral block, this was originally meant for birds so I asked if it's safe for aquariums and the clerk said yes though I'm having second thoughts because there's iodine in it. I'm thinking of adding it to my snail tank with ramshorns and a few platy fry so I'm wondering if it's safe, anyone know if it is?