I use 1500, 2000, then 2500 grit wet/dry sandpaper with water first to remove all the scratching, then use a buffing agent to remove scratching from the sandpaper. If you have deeper scratching, it would take forever to buff them out completely.
1500 and 2000 are fairly common, but 2500 isn't...
I currently have a black "tape on" background, I hate how water or humidity can sometimes get behind it.
My main reason for wanting to change the glass is because I chipped the corner during my move. I would rather spend the $80 on glass then have 90 gallons of water on my floor.
I have a 90 gal wave tank, I want to replace the rear piece of clear glass with a solid black piece. I want to drill the glass as well with four bulkheads for my two eheim canisters to hide the crappy green tubing.
Has anyone replaced a panel like that and had luck? I dont want to get it...