Difference between 6,500 and 10,000 Metal Halides

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betacrash

Guest
could someone explain the difference other than brightness. Like what is the benefit of one over the other? I have a 125 gallon and was wondering if I should get 2 or 3 MH fixtures. Last question. I have both VHO and PC fixtures, which should I use to supplement the MH's? Should they just be actinic? Thanks.
 
22caddy

22caddy

Member
could someone explain the difference other than brightness.
The brightness is the same. 6500k would be more yellow while a 10000k would be more of a whitish blue. As far as how many, what are you planning on keeping? How many watts? I would use vho to supplement and sell the pc to help cover other expenses.
 
B

betacrash

Guest
As far as what I want to keep.
Clams (maxima crocea)
Anemonies (BTA)
frogspawn, xenia, misc sponges and cucumbers.
I dont know much about stony corals since they require intense light and not many of my stores have them to even look at.
I appreciate the help.
 
nas19320

nas19320

Active Member
6500K- Generally higher PAR, faster growth, ugly yellow color bulb
10K- Blue-whitish-tint of yellow depending on bulb
 
snipe

snipe

Active Member
I thought it was the other way the lower K or "kelvin" rating you go the more blue it gets. Like the 6500 would be more blue than the 10000 and the 20000 would be super yellow.
I do know this the higher the K you go the better growth you will get out of your corals. Places that sell corals use only 20000K bulbs with no suppliment.
 
C

crm13

Guest
I agree with NAS. From what I understand, 6500K are better for growth than 10000K. Generally, 6500K MH lights also have a higher CRI than 10000K bulbs. 10000K bulbs, however, have a better look to them since the light has a "bluer," less yellow look to them. I believe that most people choose 10000K bulbs because they are a good balance between visual appeal and effect on coral growth.
 
nas19320

nas19320

Active Member
Snipe you seem to have it backwards.
The color spectrum goes something like red(5500K)-yellow(6500K)-yellowish-white-blusish(10K) and then bluer until you get to 20K which is really blue. The higher K the less growth but generally it will bring out more color in coral or at least to the eye. Like CRM said 10K is a happy medium for most. There is a study out there that shows the PAR ratings of bulbs on given ballasts and you can see that the 6500K generally has the highest PAR rating with the XM10K very close and a few times a higher PAR rating.
 
tak1968

tak1968

Member
300 to 400 ultraviolet or x-rays, 400 to 700 is the visible light spectrum, 400 to 500 is the visible uv rays that we see, 700 to 800 infrared. This is the visible light spectrum it runs from 300 to 800. 300 x-rays starting at 400 violet 450 blue, about 500 blue-green, 525 green, 575 yellow- green 600 yellow, 625 orange, 700 red. Now if this helps or not i do not know just thought someome may want to know. And i run two 250wt mh 20000k's on my 75 gal reef. Tak
 
mudplayerx

mudplayerx

Active Member
One thing is for sure, if you want to keep clams and corals, you are going to need heavy lighting. The clams definately need metal hallide.
 
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crm13

Guest
:D Ha, Tak that's pretty good if you did that off the top of your head. I think those are the figures for color wavelengths. If you're looking at bulbs, color temperature is in Kelvins. They're not the same, although, loosely related. In other words, I think that you could look at five different brands of 10000K bulbs, and they will all represent a different range of color wavelengths. The good ones peak at 10000K or higher. Not necessarily better, but truer in the sense of it's label as a 10000K bulb.
 
B

betacrash

Guest
All of this info has been really great. What I think that I am going to do is get a triple 250w from ---- and add the VHO's with actinic bulbs to supplement. Will that be too much blue?
 
soapbubble

soapbubble

New Member
Beta,
Do you ever shop at Wet Pets? The guy who owns the store if very helpful and knowledgable if you are looking for anything specific. You mentioned that not many places in your area have stoney corals, but he does carry quite a few.
 
B

betacrash

Guest
actually when I first started in the hobby I went there to buy some rock. I remember that he had a lot of cool clams. I will have to go back. Thanks.
 
nas19320

nas19320

Active Member

Originally posted by betacrash
All of this info has been really great. What I think that I am going to do is get a triple 250w from ---- and add the VHO's with actinic bulbs to supplement. Will that be too much blue?
IMO it will only be too blue if you run 20K bulbs.
 
say

say

Member
Ok this post has put things in perspective alot better for me now, but can someone tell me????
How many watts would you use for 150gal tank?? I have seen on this site itself.... 3x 4x and 6x the gallons for the wattage... Any specificis?
 
tak1968

tak1968

Member
The 20 k do give off a little blue hugh but not that muck. To me the bottem of my tank (18 in deep) looks like the buttom of the ocean when i go diving, looks like it's daylight. And with two 250wt mh bulbs on a 75gal. tank I can put anything that I want to in it. With allot of other setups that people run, thay run mh and pc at the some time. And the pc that some run are actinic bulbs and are blue. So by having 20k that are a litte blue looking the light can penetrate deeper and I only have two bulbs (the mh) to replace instead of four or six when I change out my bulbs.:) Tak
 
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