Is this tank SW
If the algae is just nuisance fuzzy stuff, a razor blade works wonders.
I have used magnetic scrapers, long handled scrapers, green scrubby pads, etc. etc. but the razor blade just seems to be the best for me. Fast and precise, and not much that the blade can't handle. (Try scrubbing nerite eggs off the glass with a scrub pad sometime LOL
If you have an acrylic tank you'll want to look into a plastic scraper blade or something soft.
hope that helps a lil bit.