Fixed the gouges in my 2.5G mini-bow last weekend. Pretty simple.

I couldnt find "aquarium scratch kits" so came plan B -- very fine
sandpaper 1500 grit and above.

None of my local auto-parts stores, home stores, or woodworking stores
had sandpaper 1500 or higher....then I tried Wal-Mart. Funny. They
had both 1500 and 2000 grit papers in the auto section. 2.95 a pack a
piece.

Besides paper, a rubbing compound is also needed for the last stage.
Walmart had some 3M for $6...but then I remembered I had some McGuires
ScratchX for my car at home. So I didnt buy any.

One vertical gouge was 6 inches long and a fourth inch wide. Rubbed
right out. 1500 perpendicular to the scratch....then 2000
perpendicular to that.

Since these scratches were on the inside -- and I had no place for my
fish -- I had to fix the scratches in place. Not sure if sand from
sandpaper would damage the fish, so instead of wet sanding, I drained
the tank down to a half inch below the scratch and dry sanded it.
Then I used the wax/polish. This did wonders. Seriously I think
liquid compounds may be all you'll need. Took 4 applications of the
stuff. One glass shop recommended I try toothpaste. Maybe that'd
work.

Was tricky not getting the wax or rubbed-particles in the water, but I
managed. I washed it really good before filling the tank back up.
Who knows what chemical additives were in ScratchX but the fish seem
fine after a week...

And to think I had my cat declawed. I thought the scratches were on
the outside.