Calcium for the Tank

[Ben]

Hi All,

A while back I purchased some Mollys and set them up in my quarantine
tank. At the end of the quarantine period (~1 month), they began to
develop white patches and looked bad. I added salt and it cleaned them
up. They've been clean and healthy for a while now (2+ months). Now
I'd like to integrate them into my main tank but I'd prefer not to add
salt to it. In reading, I found that calcium can be used as a substitute.

I'm curious if anyones had any experience with this? If so, how much
would I use per gallon?

Also, would there be a negative inpact on the other (non-brackish
loving) tankmates.

Thanks,
Ben