Faster Growth; Par or Kelvin rating

[Sebea]

In order to get better growth and color for sps, is the amount of par in a bulb, or it's kelvin rating more important?

My dilemma is that I really like the color of a 20k bulb, but I don't want to sacrifice the par that I could get with a 14k or 10k bulb. This is what I have come up with: I could upgrade my lighting from my originally planned 250w to 400w. That way, it will be easy to find a 400w 20k bulb that easily has more par than most 250w 10k and 14k bulbs.

Now, I know that with a lower kelvin rating, of course there will be more par, and that lower kelvin rating is recommended for better growth. In other words, can you get better growth and coloration with a 20k bulb that has more par than a 10k bulb?

 

[Ewan]

Let's talk about lighting an SPS tank

Great read! If you have a bit of time, it's definately worth going through that thread.

-E.

 

[FastFish720]

Short answer, Par rating

 

[gregm5]

have you considered going with a lower kelvin bulb and using actinic supplementation?

 

[Sebea]

Thanks for the link Ewan! Really helpful info.

What I would really like to see is a comparison of a 10k and a 20k bulb, both with the same par rating. Does the color spectrum of the bulb affect the growth just as much as the par rating?

Greg, I have thought about adding actinics, but I'm not convinced that they would be able to make a 10k or 14k halide look as 'blue' as a 20k...

 

[toothman]

I run 4 160vho, with 6 400 watt 10k, and the color is very natural. The 20k only are too blue for me. possibly 14k with actinic.

 

[foshizzle]

another link

http://www.reefs.org/library/talklog/s_tyree_060202.html