Trying to clean up an old tank

[whatevva]

I have an old 20 gal glass that I'd like to use for a quarantine tank. What can I use to take off all the old scale from the glass. Vinegar isn't cutting it, and a razor blade isn't doing much either. Just short of using CLR, is there anything safe that will cut through this stuff?

Thanx

[Twitterbait]

vinegar is the standard but you might need to let it set. if it is an old tank then you may just have to deal with it. some of the older tanks will have the glass etched with the stuff and it won't come off. it should disappear when you put the water in though.

[Kevin1000]

Vinegar should work if you let it sit long enough ... if your impatient then take the tank outside and let soak in a diluted muratic acid/ water. You should be able to find muratic acid at most hardware stores and many pool supply oulets.