another lighting question

[saltwaterfishlover]

know everyone has their opinion on what lights look the best for our viewing pleasure, but what bulbs do the best for coral growth.
I have a 7 month old aga rr 120 with 2 400w blueline eballasts and an icecap 660. Current bulbs are a 400w 15k xanium and a 5.5k (5500) grow bulb that came with my diamond light lumenarc 3 reflectors. vho's are 46.5" 3 actinics and one daylight.
the corals seem happier on the 5500 side more extension and puffier (frogspawn, torch and brain). the octabubble in the middle of the tank gets both worlds seams larger on the 55 side than the xanium.
I have heard for a long time iwasaki's are the best for growth but are yellowish and now am hearing the 20k's are good to. is it all a matter of opinion or tank setup or it works for me and wont work for you?
What mh bulbs or combination of mh and vho spectrums will be best to promote coral and clam growth and happiness in the tank.
I know the tank doesnt look the greatest right now. Been on vacation and my breeding pair of jawfish have been rebuilding their burrows, but comments and criticism positive and negative are greatly appreciated.
andy

[Reefland]

Welcome to Reefland!

The best bulbs for growth are the bulbs that provide higher PAR. For this, the Iwasaki's and 10k DE's have the upper hand. I have recently opted for the 10k DE bulbs due to the measure of PAR (which is lower than the Iwasaki's) and the coloration which doesn't require the actinic the Iwasaki's do to get some white/blue coloration.

Here is a link from the archives that provides more information on light than you probably care to read.

Scott Z.

[mrok12]

I am running 2 20k Radiums (400's) and 2 65K (250's) on a 120 gallon reef tank. I run the 20K for 12 hours and the 65K for 7 hours each day. I have noticed that with this combination I am getting some nice color and growth has accelerated. I found that the 400 65 k bulbs seemed to get hotter IMO and the corals really did not expand as well. For whatever reason when I added the 250 watt iwasakis and changed the 400' to radiums it got much better. The 250's prior to the change were 10 k bulbs. same photo period.

MROK12

[mrok12]

Here is a pic of both sets of light on. I like the color it gives to the tank.

[PerryinCA]

SWFL,


I think you'll find a lot of it is subjective. The Radiums seem to be the fad right now (and mostly thats all it is), and you can get great results with all the above lamps. Personally my favorite is 10k with some good actinic supplementation, or 10k along with lower wattage radium or ushio blue lamps. In the few years I have roamed these boards, the preferance has shifted from lower wattage 10ks, to Iwasakis, to Double ended 10ks, and now Radium seem to be in style. All the lamps have been around for some time, so I think its just a fad. Who knows where it will go next. I think the best thing to do would be to try lights on your tank, and come up with the thing that looks good to you and provides healthy stock.


-Perry