How To Clean Calcium Off A Fish Tank. You can also mix a paste with vinegar and baking soda to clean calcium. They are nontoxic and won’t harm your fish if you leave a small amount of residue behind.
Removing calcium deposits from plastic is easy. If the plastic is too large to fit into your sink, simply moisten a wash cloth with pure vinegar, and rub over the calcium deposits until they are gone. What is the best way to get more calcium?