Help with cleaning algae on acrylic

[elegant_reefer]

I went on vacation for a few days and when I got back, my whole viewing surface was covered with algae. I don't know what kind of algae it is but it is extremely stubborn and won't easily come off. If anybody knows how to clean this off without any scratching please let me know. As you can see, the previous owner was not so careful with keeping it scratch free. Thanks all!

 

[wicked demon]

Get an acryilic scratch remover kit, like less than $20 to fix scratches, and there are acrylic safe scrubers and scrapers available. The scratch remover kit can be used with the coral and fish in the tank with no ill effects, just do a water change when your done.