Hi Chris,
You have a couple of options, some better than others. Chemically attacking the aiptasia works, but isn't really the best route if you have a large infestation. Joes Juice works well, but for the cost isn't really economical use to control a large population.
Naturally, there are a couple of different ways. Peppermint shrimp have been known to eat aiptasia, although it's not their preferred food source. There is generally enough other food in an established reef that they won't make a big dent in the aiptasia population.
The best way, IMO, is the aiptasia eating nudibranch--Berghia. They're a sea slug that only eat aiptasia. Do a search on this site about berghia and you'll learn a lot. They're expensive and hard to come by, but they kick butt.
No matter which way you go, it takes some time to get everything under control. A matter of months maybe.
Where in IA you from?
Nate