Johnc,
I have been there!! Clean the glass in the morning and by afternoon it's covered with green!
I finally ordered a really good clean-up crew and they have taken care of the problem. I see from your profile you have a 46 gal. I would get 45 or 50 snails and 25 or so hermit crabs, mostly blue-leg.
One thing to check before you buy the inverts: have you tested your water for phosphates? If not, your phosphate level could be high and that would be the primary cause of your algea problem. Using a good phosphate sponge will help alot.
Jim