http://www.championlighting.com/prod...4&cat=0&page=1
Just picked up one of these from OA and glued it to the back of my MagFloat 350 with crazy glue. It scraped away coraline algae like its slime and especially where you can't normally get to with a magnet cleaner. I thought i would have problems controlling it but it was a piece of cake. No need to use those Kent scrapers with stainless steel insert anymore. For 15 bucks, its worth every penny. It has a stainless steel blade that is retractable but instead of leaving it in the scraper, I removed mine, rinse in fresh water and air dried it. If you have problems with coraline algae especially on the edges of your glass, you won't regret getting this nifty device. Such a simple idea but yet so effective.
Unfortunately if you have an acrylic tank, i don't think this will work for you.