Good luck. I wish it were as easy to remove as people make it out to be. It may be when it's only on there a few months, but after being on the glass for years, I'm convinced it cannot be removed.
I picked up a used 90g saltwater because several people on here insisted the calcium could be taken off. Yeah, the bulk came off with a razor, and some more with vinegar. The last bit I tried getting off with CLR (Calcium, Lime, Rust) as suggested on here, and no luck. I'm convinced it cannot be taken off if it's been on the glass long enough. I'm now looking at selling the tank as a reptile tank and buying another 90g to replace this one.
I picked up a used 90g saltwater because several people on here insisted the calcium could be taken off. Yeah, the bulk came off with a razor, and some more with vinegar. The last bit I tried getting off with CLR (Calcium, Lime, Rust) as suggested on here, and no luck. I'm convinced it cannot be taken off if it's been on the glass long enough. I'm now looking at selling the tank as a reptile tank and buying another 90g to replace this one.