Hard Water Stains?

[Rolance]

This tank sat in a shed for 2 years. I got it out, cleaned it, and set it up about 8 months ago. I didn't notice the hard water stains when I set it up, but it's been bothering me for quite a while now.
I've tried scrubbing it and scraping it it just won't come off. The water is crystal clear when you look in from the top but this line kills me.
Is this hard water stain?
Is there a way I can get this off without having to take the tank down?

 

[henrysdad]

This tank sat in a shed for 2 years. I got it out, cleaned it, and set it up about 8 months ago. I didn't notice the hard water stains when I set it up, but it's been bothering me for quite a while now.
I've tried scrubbing it and scraping it it just won't come off. The water is crystal clear when you look in from the top but this line kills me.
Is this hard water stain?
Is there a way I can get this off without having to take the tank down?
View attachment 294254

A disposable double edged razor blade works great. Just be careful the blades are thin sharp and break easy.

 

[Alan26]

scrub with a little white vinegar during every water change until gone.

 

[Rolance]

I tried everything I could without having to move fish out and completely take it all out but nothing worked.

I'm now planning on moving all my fish, substrate, driftwood, and filter to a 29 gallon for a couple weeks while we are laying floors in my house. During that time I plan on using a compound I saw on YouTube to remove the hard water stains.

Do y'all think my 5 rainbowfish, 7 neon tetras, and 1 bristlenose will do ok in the 30 gal for a couple of weeks?

 

[t-bone]

Use cerium oxide and one of those cheap random orbital buffers with a terry cloth pad. I had the same problem. That is the only thing I could find to remove it. Some of the spots in my glass were actually pitted a little. It polished out real nice though. Just takes a little time. Here is a before and after on a test piece. It will polish out scratches but they have to be VERY light though.

 

[Rolance]

Awesome thanks!