I was wondering if small quanitys of copper have affects on inverts. (octos in particular). Surely there is copper deposits in the ocean and even if theres not, there must be pipes that branch off from copper tubinng going into the ocean. Just a little thought. I dont think that it really hurts them in small quanitys. i wash my hands with soap water that comes from copper pipes and my starfish shows no signs of allergicness. Also an update. My black algea, diatom, problem has ceased dramaticly and i am still tackleing it with ro water changes. Wondering about the copper thing above tho.