Tank Cleaning Advice (Hard to remove Stains)

[BadBrad]

Okay an update. The lemon didn’t work so I have moved to 1000 grit sandpaper. It seems to make a little impact at a time. I believe I am going to take the tank apart completely to work on it. I am also going to go ahead and do some scratch removal while I am at it.
I have two questions:
1. Any suggestions on taking the bottom trim off without cutting it off? I would like to keep it and use it if possible.
2. Any good suggestions on scratch removal?

 

[duanes]

There are certain glass discolorations that occur over the years, that are impossible to remove.
The 55 gal tank below had a haze that could never be removed, no matter what I tried, strong acids, bases, sandpaper.
I believe it actuallypermeated inside the pane of glass. I ended up using the tank as a sump.

 

[BadBrad]

Okay an update. The lemon didn’t work so I have moved to 1000 grit sandpaper. It seems to make a little impact at a time. I believe I am going to take the tank apart completely to work on it. I am also going to go ahead and do some scratch removal while I am at it.
I have two questions:
1. Any suggestions on taking the bottom trim off without cutting it off? I would like to keep it and use it if possible.
2. Any good suggestions on scratch removal?

There are certain glass discolorations that occur over the years, that are impossible to remove.
The 55 gal tank below had a haze that could never be removed, no matter what I tried, strong acids, bases, sandpaper.
I believe it actuallypermeated inside the pane of glass. I ended up using the tank as a sump.

I sure hope that’s not the case in this situation. But it could be.