Before you go adding a cleanup crew you'll want to make sure your nitrates, nitrites and ammonia are all at zero for a minimum of one week.
Elias is right; as your algae diminish your cleanup crew will have less to feed on and start to die off. Get some GFO going and when you're ready for some Cheato ask in this forum. People are always looking to get rid of it. As a matter of fact I'm ready to get rid of some of mine. Also a remote sand bed in your sump will also be a good idea. It was Denny that put me onto that
Good luck and have fun with your tank.