Here is the article. I may have misspoken. I don't see 2 day on there. Although I do agree that more sensitive corals like acros should be sent overnight. This was a reefer to reefer shipment with 2 well established tanks and I don't recommend shipping like this for newer tanks or for reefers purchasing from vendors as there is no guarantee that 2 day will get you your corals safe. There were a lot of considerations that came into play and all were accounted for. Climate, temp where they were sent and the climate they arrived in and time of year for that temp. Also the forecast temp. This thread isn't to say that 2 day is preferred, I am just saying that it was a challenge and it worked in our case. It might not in every. http://www.advancedaquarist.com/2005/11/tips Thanks everyone. They sure are beautiful pieces and I am really happy with them.