I had really bad algae in my tank, i would clean it and almost the next day it wouuld come back. I didn't like the idea of using a chemical algae remover, it made me kinda nervous. I did a little research and found that algae needs phosphates to live and grow, so i got a phosphate test for my tank water and it was pretty high (a result of the breakdown of food waste and poo from my messy turtle). I tried a number of different filter media that removes phosphates but none of them seemed to make much of a dent in the levels when i tested them, so i decided to bring out the big guns. I got a "Phos-Ban Reactor"
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=11586&Ntt=phos%20ban&Ntk=All&Ntx=mode+matchallpartial&Np=1&pc=1&N=0&Nty=1 and a water pump to operate it and in a couple days my phosphate levels were at zero. Ever since i haven't had any algae growing in my tank at all.
I know it's a kinda crazy solution to something that really isn't a big problem, but i love hooking tihngs up and making them work, so it was fun for me, and the algae really annoyed me since i work so hard at keeping the tank clean.