MH/VHO Retrofit

[powderblue]

Hi, I am going to put a 60 inch icecap retrofit kit on a 140. It will have 3 250 watt MH bulbs and 2 140 watt VHO flourescents.
I would like to maintain a wide variety of corals.
What would be the ideal light combination to maximize the livelihood of the corals I intend to purchase?
I am currently planning this:
2 6500 K 250 W MH bulbs
1 10000K 250 W MH bulb
2 14000K 140 W VHO bulbs
Is that a sufficient spread, or should I dedicate all three MH bulbs to 6500K and use the VHOs for 20000K?
I appreciate your help!

 

[mr . salty]

If it was me,I would go with a higher k-value on all three MH's,and use either a actinic blue,or 50/50 on the VHO.

 

[powderblue]

what k value is the actinic blue?

 

[mr . salty]

Actinic is the MAX k-value.K-value,simply put,measures the ammount of blue light.Or the absence of yellow,red,and white light.Actinic is all blue.

 

[powderblue]

so, go with 20000k on both vhos and maybe
1 6500k mh with 2 10000k mhs?
are you sure that would provide enough artificial daylight?

 

[sonny]

The lights don't have to be higher k values to be good for the corals... The sun isn't all blue light. The thing that happens is that water filters out all of the red light. The deeper you go, the less red light penetrates the water. This happens in aquariums too, but not as much since most tanks are not more than 24 inches deep. One thing you may want to consider is the cost of lamps. MH bulbs need to be replaced every 12-18 months. Since high k lamps are almost double the cost, you may want to consider using 6500 k lamps. I am planning a 135 gallon reef, and will be using two 6500 K lamps one on each end, and one 20,000 K lamp in the middle. I will also be using two 72" VHO actinic lamps. This gives flexibility to simulate dawn to dusk effects too.
I like your original plan. Let the Actinic come on about 8am, then the 6500 K MH's come on around 10am, then the 20,000 K MH about 1pm for 3-4 hours, then you could leave the 6500 K lamps on until 6pm, and actinics off about 8pm. You could also shift the times so it will be on when you're there to enjoy looking at them. Lighting is very subjective, and the only PERSON you need to please is yourself. Look at tanks in LFS's and decide what you like. The 10,000 K lamps are very pleasing to most people, but they are usually over $100 each! The most important ones to please however, are the corals!
Sonny

 

[powderblue]

I don't understand the difference between the 20000K bulbs and the actinic bulbs. Are they not the same thing?

 

[sonny]

The 20,000 K lamps I am talking about are MH lamps. They are very blue, but do have a white cast to them. I don't think you'd want to use them as your main lighting. Some people do that though. Flourescent Actinic lamps are very blue, almost like blacklights (if you remember the 70's). I don't know what the color temp is, I suspect 30,000 or 40,000 K. The combination of 6500 K MH and VHO actinic will give you a nice look. I don't think VHO lamps give you the color temp. They are sold as actinic, actinic white, and aqua-sun. They are made for aquariums though. If you get a 20,000 K MH, you might want to mix in some of the other colors of VHO.
Sonny

 

[burnnspy]

Its good to see some starting with the right lighting from the begining.
I would go with 3-6500K(or 10000K) and the actinic 03 VHO bulbs.
BurnNSpy

 

[powderblue]

OK, I have decided to go with 2 6500K MHs, 1
10000K MH, and 2 Actinic VHOs.
I appreciate all the input. Thanks for the help!