Well give it 3-4 weeks and see how they do. Keep you water changes going and if the polyps do well, that means your tank is good condition. You can try getting hardier stuff. Get a book on corals (ISBN 1-890087-47-5 is a great book, called Aquarium Corals, Selection, Husbandry, and Natural History). Make sure you get species appropriate for your tank. Some like more light, others like less. Some like high water flow, other's like moderate, and other's like little. See what works best for your tank.
Also, if you're keeping coral next to each other (in close proximity that is) look for coral that are not notorious for strong stings like Euphyllia and Galaxea species. I hope this helps.