Calcium build up in freshwater aquariums

Question
How are ya now?
Well, this is my perdicament, I purchased a used 65 gal. aquarium and it has alot of calcium built up on the glass. What can I use to remove this calcium other then a razor blade, that just takes way to long and doesnt do that good of a job. Any advice at all will be more then helpful, thanks for your time!

cheers,
Mike

Answer
Hi Mike,
Looks like you have your work cut out for you. There are a number of industrial cleaners availble at Target, Home Depot, etc. One I've seen advertised lately is CLR (stands for Calcium, Lime, Rust). You spray it on and wait a little while and (hopefully as advertised) it will remove the calcium.
The most important thing in using these cleaners is to be sure to wash the aquarium out with fresh water very thoroughly before you set up your tank.
The worst chemical to get in a fish tank is amonia, because that will instantly kill anything you put in the tank. So after you clean it up, wash the chemicals out with regular dish soap,  then spray it clean with a hose.
Hope this helps,
Nori