honda2sk,
Thank you for contacting us with your question. The lights we have at our Aquaculture Coral & Marine Life Facility are Double Ended 400 watt HQI Metal Halide lights. The lights are kept between 12 to 18†depending on the specific needs of the corals in that row.
When adding a new coral to your aquarium with existing ones, we recommend placing 5 to 10 layers of the screening material (such as cut out pieces of nylon mesh) above just the one or two new corals during the first few weeks. (Please place the new arrivals at the bottom, or bottom corner of your aquarium.) You would then remove one layer a day until the coral displays full coloration and appears to be fully expanded. You may then slowly inch the coral to its preferred location over the next month or so. This will ensure the existing corals in your tank will not become distressed and still allow you to acclimate your new arrivals slowly to their new lighting system.
We hope this information is helpful to you and if you have any further questions please contact us at 1-800-334-3699.
Stacie R.
Technical Support
Drs Foster & Smith