Buyer beward--most of your answers suggested freshwater animals. Swimmer dude gave you the best advice, so I won't reiterate all of his points, but I'll append his list.
Different people have different experiences with Phosban; some find it useful, others don't. It won't be a guaranteed cure, but it also won't hurt to try.
However, a protein skimmer will help, as it removes some phosphates (and to the nay-sayers: yes it does. *Ionized* phosphate is polarized; I'm not calling a protein skimmer a fix, I'm calling it a useful aid). If you aren't running one, it would help to start.
I have to reinforce the over-feeding situation. It's easily the top cause of algae.
As for what will eat the algae, it really depends on the algae that's currently growing. No matter what, mandarins will not help at all; they are strictly carnivores.
The most common nuisance algae is (at least at first) hair algae, which will be eaten by the popular zebrasoma tangs, such as the yellow tang. Most small snails will feast as well (such as the popular astrea and turbo snails), some crabs (but beware...most crabs will eventually want meat), some shrimps, and some urchins. Lawnmower blennies are popular as well. What you should get is really going to depend on how big your tank is and what you eventually plan on keeping.
Finally, I'd like to point out that increased water movement will help algae from becoming established, but it won't cure the algae already there. Make sure anything you use to control the situation includes increased flow, and make sure that the flow is throughout the tank. Deadspots are sure to harbor algae again sooner or later.