Do you know the type of algae it is or can you post a pic?
For smaller tanks I find Cerith snails to be one of the best with film aglae and diatoms. A few nassarius snails wouldn't hurt either to maintain the sandbed and help eliminate uneaten foods. A mix of each would be best, 10-20 total.
NO Fluorescent lighting can be a bit of a contributor as well. Especially lower watt types. They will normally emit much of their light in the red spectrum level which promotes undesirable algae growth. Do you know the kelvin rating you have now and the age of the bulb?
What do you normally feed the tank?
I also find that maintaining the water chem (alk
) a little higher than NSW
also help alot. It inhibits the lesser algaes ability to gain nutrient from the water. You may not be maintaining a reef tank, but proper chem does help.