MH light question.. 14000K 20000K?

teen

Active Member
Originally Posted by SaltFan
Well, actually. Wouldn't 6700k be the best then? Supplimenting with Actinic? Being that 6700k is the sun at high noon?
im pretty sure as mud sayed, 6700k wont support corals.
i just ordered a 10k 250 watt pendant, and i dont plan on supplementing with actinic because i like the 10k look, and i would like to get my corals growing really good first, then maybe switch over to a 14k bulb in a few months.
 

fisherson

Member
I just got a light setup with 2 175's the guy sent me 1 14k and 1 20k the 14 is very blue and the 20k is much more real looking. I don't know which i like better so i kept them. if i had to choose right now i'd go with 14k but i want to see what happens when i add corals to both sides and see what grows faster...
it's cool it goes from 14k blue melding into 20k white. I like it
 

teen

Active Member
Originally Posted by fisherson
I just got a light setup with 2 175's the guy sent me 1 14k and 1 20k the 14 is very blue and the 20k is much more real looking. I don't know which i like better so i kept them. if i had to choose right now i'd go with 14k but i want to see what happens when i add corals to both sides and see what grows faster...
it's cool it goes from 14k blue melding into 20k white. I like it
are you sure he didnt just label the bulbs wrong, or maybe he sent you 10k and 14k. the 20k should be the most blue, 14k a mix of blue and white, and 10k the most white.
 

hurt

Active Member
A 6500K will grow corals the fastest. Iwasaki 6500K puts out far more PAR than any other bulb I have ever seen tested. However, once you go below 6500K to 5000K(380nm-below) and below, then yes this spectrum is not usefull to corals. But generally speaking the lower the K value(6500K) the higher the PAR(greater growth). The higher the K value(20000K) the lower the PAR, but the better the coloration in your corals. Also, a lower rated K bulb will last much longer than a higher rated K bulb. A 6500K can last 2 years without a significant shift in spectrum. However most 20K bulbs last only 3 months before their spectrum drastically shifts. So its a trade off between growth, coloration, and longevity of the bulbs
Google:
Dana Riddle
Cnidarianreef lamp tests
 

fisherson

Member
wow really? the one that was labled 20k is very realistic looking if you know what i mean really clear and white and the one that was 14 is pretty blue. but not as blue as some i've seen. Maybe i actually have a 10k..
 

hurt

Active Member
Actually a 20K is not very realistic looking, unless you are 15 feet under the ocean-then yes. A 10K is designed to look as if it were 4-5 feet under the ocean, while the 6500K is right at the ocean surface at high noon. I personally run 2 10K XM's because of their very high PAR readings(530) along with 2 VHO super actinics. On the other hand a 20K XM 250w MH bulb produces only 270 PAR on my ballasts. I have seen some Ushio bulbs however in which the 10K and 14K both produce the same PAR #'s. In such case I would go with the 14K Ushio for better coloration.
 

tony detroit

Active Member
Originally Posted by SaltFan
Umm HUH?? If he has the reef going, and had no lights, water quality would mean absoultely nothing.... 14k is a very good light. Beats the 10k and not many are high on the 20k.
I don't know what you're talking about. I've used every spectrum of bulb and have noticed little to no change at all in growth.
Growth is in water quality/conditions. Period.
Bulbs will alter colors and improve growth, but the majority of growth is in the water quality, provided you're already running a good amount of light. I dunno where you get your facts from, but I get mine from experience.
For your input on 14K vs 20K. Most 14's will grow better than a 20, based on what "experts" say, but IME not anything noticeable. However in most cases a 14K WILL NOT grow better than a 10K, or better yet a 6.5K.
IME the 20K has been most appealing to my eyes. I never noticed a decline in coral growth at all.
He asked for suggestions on other intensities. If you don't have anything useful to input to the thread find one you can help in, and comment on something that you yourself have done.
 

saltfan

Active Member
Originally Posted by tony detroit
I don't know what you're talking about. I've used every spectrum of bulb and have noticed little to no change at all in growth.
Growth is in water quality/conditions. Period.
Bulbs will alter colors and improve growth, but the majority of growth is in the water quality, provided you're already running a good amount of light. I dunno where you get your facts from, but I get mine from experience.
For your input on 14K vs 20K. Most 14's will grow better than a 20, based on what "experts" say, but IME not anything noticeable. However in most cases a 14K WILL NOT grow better than a 10K, or better yet a 6.5K.
IME the 20K has been most appealing to my eyes. I never noticed a decline in coral growth at all.
He asked for suggestions on other intensities. If you don't have anything useful to input to the thread find one you can help in, and comment on something that you yourself have done.
Ok, Mr. Expert. Turn your lights off all day and see how your Corals grown then. Then when they are all dead, don't come whining to me that your water quality was perfect, and can't figure out why all your corals died.
And also, if 6700k is the sun at high noon, and you could get them in the correct wattage for your specific needs, why in the hell wouldn't it be good?? If its good enough for hte ocean, why not your tank then?? !!
 

fishieness

Active Member
Originally Posted by SaltFan
And also, if 6700k is the sun at high noon, and you could get them in the correct wattage for your specific needs, why in the hell wouldn't it be good?? If its good enough for hte ocean, why not your tank then?? !!
That is mearly the color. The lower the K, the higher the PAR rating and the deeper the light is able to penetrate the water. That is what is being discused about the spectrum. Not only the color. The lower the bulb, the higher the PAR.
 

mudplayerx

Active Member
I apologize about my erroneous statement on 6700K bulbs. I was under the impression that they were not suitable for coral growth due to the fact that I have never heard of anyone using them. My guess is that they are very very yellow in color, so many people choose to use 10k.
 

fishieness

Active Member
Originally Posted by mudplayerx
I apologize about my erroneous statement on 6700K bulbs. I was under the impression that they were not suitable for coral growth due to the fact that I have never heard of anyone using them. My guess is that they are very very yellow in color, so many people choose to use 10k.
exactly. They are great for growth because the PAR rating is very high compared to higher K ratings. But they are very very yellow and not very good for color. Some people use a 6500K on their frag or growout tank, and then let it color up in their main tank before selling.
 
N

n_sarno

Guest
wow I just asked for advice I didnt want to waste my time seeing people fight back in forth.. thanks anyway
 

mudplayerx

Active Member
Originally Posted by N_Sarno
wow I just asked for advice I didnt want to waste my time seeing people fight back in forth.. thanks anyway
Just ignore bickering when you see it. It tends to dissapate quickly on these boards
 

tony detroit

Active Member
Originally Posted by SaltFan
Ok, Mr. Expert. Turn your lights off all day and see how your Corals grown then. Then when they are all dead, don't come whining to me that your water quality was perfect, and can't figure out why all your corals died.
And also, if 6700k is the sun at high noon, and you could get them in the correct wattage for your specific needs, why in the hell wouldn't it be good?? If its good enough for hte ocean, why not your tank then?? !!
Pay attention to the TITLE of the thread. Answer the guys question.
I said it before, and I'll say it again, if you don't have something to contribute, don't. We're not talking about lights being on or off. We're talking about color.
And again, in case you missed it the first time around, growth is in good water quality, not in the bulb. Ask any reefkeeper that's been in the hobby for more than a couple years. Growth doesn't change regardless of the bulb they're running.
 
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