Acclimating corals from Online purchase

I ordered 7 Coral frags online about a week ago. Yesterday I received my shipment, which has turned out to be not doing so well. I have many corals in the tank that are very similar to the ones being brought in, beings zoanthids and mushrooms. Only 1 or the 7 corals has even started to open up, and that is doing so in a very limited way. I was wondering if anyone had ideas on how to get them acclimated to start opening, or how long I should give them to acclimate to the tank, as I have never ordered from an online location before. I do have them lower in the tank for the light spectrum, with very stable perimeters in the tank. All my current and existing corals are doing very well. Thanks for the help!