The lighting of my reef tank is done with a twin 250w 14,000k Arcadia Metal Halide unit which is just short of 4ft, its 110cm. I have this unit suspended from the ceiling with cables. The glass cover under the lamps are 8cm from the waters surface. Any closer and I tend to find it causes the water to get too hot. The main halides are on from 11am to 8pm every day. The lighting I have chosen has given me the oportunity to have anything in the tank, as if I had normal flourescents, I wouldnt get the power and light spectrum needed to keep certain things such as hard corals. Metal Halides are well worth the investment but they do not come cheap. You would typically pay between £600 and £700 for the Arcadia Light Unit. The new Series 4 is better than the Series 3, but does the same job.

Arcadia Series 3, twin 250w 14,000k 110cm
The Arcadia light unit on the display tank provides the whole tank with light all the way to the sand bed as the metal halide bulbs are 14,000 Kelvins each and have a penetrating depth of over 65cm. This light unit gives off a lof of heat but also a lot of light, its an easy choice, go with the light.

Twin 30w Actinic Tubes
Running down each side of the halides are 30w Actinic tubes which do the UV part of the spectrum. The Actinic lights are on from 9.00am to 10pm every day. The actinic lights are built into the main Arcadia Series 3 pendant unit and run the whole length of each side. Its very important to have actinic lighting.

LED Moonlights
In addition to the Actinics and Halides, I have moonlight LED's. I have 6 blue LED's which have a light rating of 470nm which is as close to natural moonlight as you can get. These are powered by a 300ma 12v transformer. The LED's are stuck to the back UV deflector on the main light unit as per the photo.

T5 Sump Lights
A lot of people say you should have a certain type of light over your sump, but i have seen so many different types of light, i figure it doesnt make too much difference. The lights i have on my sump are 2x 13w T5 lights from B & Q and a 24w Compact T5 by Interpet. They seem to do the job great and they only cost about £15 each. I have these lights on 24 hours a day. The Compact T5 gives off 7100k of light and the other two lights are 3400k each. The Interpet unit you can normally buy for around £25 to £30 including the lamp itself. I must admit when i put it on my sump as well as the ones from B&Q you can see how much whiter the light is and how quickly it makes stuff grow. They are well worth the money and very cheap to run unlike halides.