MagFloat brand makes an acrylic safe scraper. I use them in my kids' 3 gallon acrylic tanks, and they work great. Also, many of the commercial scrapers on handles have glass and acrylic versions, with the difference visible in the color of the pads (ex. blue vs. white). For the outside, you could use a cotton baby washcloth moistened with plain water, or you could try one of the specialty cloths (like chris's post mentioned), and I imagine you could find one at Wally World or another store fairly easily. Just as an example, Bed Bath and Beyond sells an assortment of cloths for a variety of surfaces. I bought a special cloth to clean our computer screens, plus I get 20% off and $5 off coupons in the mail from them all the time. Just some thoughts... Good luck T!