Quick How do i remove Hard water stains from a used tank.

I have a thin hard water stain across my 29g and tried vinegar along with the razor blade..... No help. I even went to the extreme of trying Lime-Away soaked in to a paper towel layed on the glass. No help. I'm just living with it.
 
Anybody find something that works well? I just bought a few used tanks yesterday that have a fair bit of hard water stains on em.

We have all told you what has worked well for us in the past. Now it's up to you to choose which method you want to use and give it a go. If one method doesn't work for you try another.:) Good luck and enjoy your tanks!
 
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