questions on used light

[grozier]

I just bought a Coralife Aqualight Pro Metal Halide Aquarium Light Fixture, 3X250W HQI & 4X96W Compact Fluorescents, 72 inch and I had a couple questions? First how long do you run MH and does anybody have the three on separate timers to simulate the sun going over? what wattage do people use(they gave me 14k 20k and something else) also what is the difference in the actincs? two were burnt out when I got it but they used what looks like blue in the front and purple in the back?

This light is monstrous and fits my tank to the fullest, I bought it on CL for 250. Didn't seem to bad of a price for a 1yr and a half or so light. They also upgraded the fans inside with some big ass computer fans and a fan controller.

Any lighting input would be must helpful.

 

[BL1]

Really the colors will be up to you and what you think looks best on your tank. The 10k bulbs will give your tank a yellower look with the 14/15k being slightly bluer and the 20k being the bluest MH bulb. For double-ended 250w bulbs the best coral growth you'll get is from the XM 250w 10k bulb, it's got the best tested PAR numbers. With the compact fluorescent bulbs you can use them to supplement the color you like. The difference between the purple and actinic bulbs is just that they'll make different colored corals stand out more. If you like your tank to look more blue you could just get the 20k MH bulbs or, you could get the 10k or 14k ones and make the tank look more blue by adding the CF bulbs in the color you want.

 

[grozier]

Do the actinics really do anything? I thought they helped with photosynthesis?