do i need actinics with a 14k bulb?

[grendl]

The lights over the large sell tank at Fujis are 2x250 14ks. I think they illuminate the tank beautifully. The lights are mounted someone high over the water, but the tank is very shallow.

My tank is a 90, & I believe I will stick with the 14ks on my second purchase of lights. I *might* drop down to 12ks if its too blue, but I dont know that it would make a HUGE difference. I will have to eyeball it myself. I have the ballast to push I think 4, 110 VHO, though I am going to follow The Masters (Matt) lead & only run 2 for a savings on light money. Currently I have 2 110 actinics. When I finally get to see how this stuff looks hooked up, I am going to appreciate the flexibility I have with the kit I have, & enjoy working with photoperiods.

I was considering something like 1 110 act coming on early in the AM, the 2nd 110 (I was considering a low k bulb) kick on a short time after that.... a short time later, kick on the 2x250s, then shut the lights down in reverse for a close to dusk to dawn effect, & some low K juice to see how it balances out the blue.

 

[MattG]

Annetate: i know a little about the different color temps. I think that we are just seeing the quote in a different way :beer:

Travis: you wont be able to have the vhos come on at different times. 1-4 vho bulbs are ran off the single URI ballast and they all go off/on at the same time. So its all vho bulbs on then mh's unless you wanted to add a seperate ballast to drive a different light for the dawn/dusk effect. This is unnecesary IMO. You might want to stager the halides turning on 10 mins or so from each other. When halides are first started up they pull more juice then when they are normally running and if its on the same breaker as all your other equipment it can sometimes cause problems.

 

[firefish2020]

Ok here we go with my thoughts on this.
I run 2X150 DE (Coralife brand) 10Ks on the 120, they give me good light great light at the top to mid level, after that the PAR falls off and is perfect for the softies and blastos on the bottom.
I ran 2X14K Hamilton bulbs for 6 months last year. I noticed great color but an almost immediate slowing of growth in the coral in the system. I am quite familiar with light spectrum and light theory and wont bore you with the details but in basics it goes like this. The K rating or Kelvin rating is not a universal standard therefor it matters little as to how close to natural sunlight a particular brand will claim. It only refers to a temperature at which combustion of the internal gasses in a closed vacum reaches a peak level transmitting light-photons-phosphorus-bla bla bla not important to the average reefer IMO.

The important thing here as I see it is this. You need to ask yourself do you want growth, color or a fine balance of both. I dont think you can have both without sacrificing something else, in this case you would need more wattage or a more powerful ballast to drive the bulbs to an acceptable level.

Personally I like bulbs ladled 10K and supplemented by T-5 or VHO actinic WOW did I say that? I don't have T-5s or VHOs but IMO I like the look of them for actinic purposes. I use 2X96 Watt PC rated near 470nm that's blue enough to blend the 10Ks to a nice sharp natural look for me. Hope this helps a bit, dont be missled by all that K and nm stuff, just look at as many tanks as you can, then decide what you like or better still what your coral(s) need.

 

[phljess]

This is the light study I believe Annetate is referring to http://www.cnidarianreef.com/lamps.cfm It shows the difference between many commonly used bulbs in reef aquaria. I believe all the study are done using SE 250 watt bulbs. It is a truly eye opening study showing how different lamps produce various levels of PAR and other qualities of light.

 

[annetate]

<a href=showthread.php?s=&postid=6956252#post6956252 target=_blank>Originally posted</a> by phljess
This is the light study I believe Annetate is referring to... http://www.cnidarianreef.com/lamps.cfm

although that is not the site i am refering to, it is a very helpful study. thanks for the input! I was refering to a site that did the spectrum at a depth of 20 ft in the ocean ( i believe a typical depth for most corals) and did a comparison of various bulbs. see if anyone can find that? i did once but have since lost it.

 

[annetate]

i bet reefer_for_life never thought he'd start this discussion with that simple question haha

 

[reefer_for_life]

i know. im more confused now than when i started!! want to thank everyone for all the opinions, and if you have anything else to add, lets keep the discussion going. im sure it will be helpful to others venturing into the metal halide world. but i think ive changes my mind lol. think im going to get 2x175watt icecap ballasts with 10k XM bulbs and 4x95watt VHO actinics. how does this setup sound? where is a good place online to get icecap lighting? thanks again.

 

[MattG]

Since you seem to be set on the 175 watters you might take a look at these articles by Sanjay Joshi comparing various bulbs. Lots of info for each bulb (spectral analysis, ppfd, etc).

http://www.advancedaquarist.com/2005/11/aafeature2/view?searchterm=None

http://www.advancedaquarist.com/2005/12/review/view?searchterm=None

If i was to try a 175 watt bulb i would be very tempted to try iwasakis new 14k. Personally i dont like the way XM 10k's look but once again that is just a personal preference. Cheapest plac to order the icecap that i have seen is www.thereefstop.com.