Lights Help...

wamp

wamp

Active Member
Hello all,
I am currently setting up my 65gallon tank... It is 36x18x24..
I would like to run 250w halides. I do not want to run any supplemental lights with it due to heat...
So, with a budget that allows some nice stuff, which type bulb would you choose. It will be an electronic ballast.
I will want to keep mostly SPS... Not really a big clam fan but the lower light ones are an option...
Please, Choose my bulb...Or.... Give me some other options...
Lighting is not my strong suit..
 
michaeltx

michaeltx

Moderator
I THINK the 10K is the bright white color and the 20K is the blueish color. brand bulb I have no experience other than 65k saki
from what I understand is that the 10 and 20K doesnt need atinic but for our viewing pleasure. If you like the bright white color I would go 10K but if you want a bluer color go the 20K
but growth if I remember the lower the better.
65K best for growth but horrible on color
10K good growth bright white color
20k growth blueish tint to color
50k growth I dont know purple color
I think this is right though. maybe someone else can agree or disagree with it.
Mike
 
rickster

rickster

Member
I think Mike meant 6.5K and 5.0K, not 65K or 50K...its tough to tell if he meant (thousands or kelvin)
On continuous light sources it is possible to measure the color produced using kelvins as the measure.
The lower the number the "redder" the color until it reaches into the invisible infrared range of the spectrum.
The larger the number the "bluer" the light until it reaces int the invisible ultraviolet range of the spectrum.
Sunlight at noon is around 5400 kelvin and direct sunlight is about 6000 kelvin
20000 kelvin is the color of a clear blue sky, and makes for some cool aquarium affects and why that is a popular color temperature.
I think the most important number for aquarists is watts/gallon...at least that seems to be the consensus.
 
krunk

krunk

Member

Originally posted by Rickster
I think the most important number for aquarists is watts/gallon...at least that seems to be the consensus.

nope, wpg is a bad comparison.
 
michaeltx

michaeltx

Moderator
actually yeah 6.5K but the 50K is real I dont hink think make it but for a 175 watt though I saw them somewhere have to look it up and see but the pics are PURPLE deep purple at that.
I think WPG is intensity.
actually you can take the same number of watts over a tank of MH and PC and there is big difference in intensity. thats why alot of people have been trying to get away from the WPG rule of thumb.
lets say I have 495 watts of PC on my 100 gallon and on another 100 gallon I have 2-250 watt MH on that one. thats 5 WPG the one with the MH lights will be more intense then the one with PC and there will be more light for the critters in the tank to use in the MH lite tank.
but anyway thats why people are trying to get away from the WPG rule and going for a type of lighting and tank volume to critters.
Mike
 
attml

attml

Active Member
Rickster,
PARs (Photosynthetic Available Radiation) are actually a measurement of light saturation. Light will only travel through water so far. PARs are the measurement of the intensity of light as it travels through water. If you put a 250w 10k PC light next to a 250w 10k Metal Halide light and measured how bright they each are at 20 inches of water depth you would be measuring their PAR value. Due to the differences in the intensity of the type of light they each are the Metal Halide intensity would be higher because it is a more intense type of light even though they are both the same wattage (250w) and they both burn at the same color temperature (10K). HTH!
 
rickster

rickster

Member
OK I think I am getting it. A MH bulb packs a lot more wattage into a smaller distribution area and thus has deeper penetration into the water column, whereas a pc distributes the same amount of wattage across a larger area and thus cannot penetrate as deep...lowering the par.
PS: do you know where to get a 250W PC at any color range? the most that I have seen is 96W
 
michaeltx

michaeltx

Moderator
I dont think the make anything anove a 96 ;-)
I got 495 from playing with numbers economics would be horrible too for that much pc on a tank LOL
I think attml was just using the same wattage no particular bulbe the differences are all going to be the same but for explanation purposes it works ;-Þ
Mike
 
rickster

rickster

Member
The only thing that I can find that radiates at 50000 kelvin is a very dark (black body)star....I think this is well into the invisible part of the spectrum...I have found some 1000 W sodium bulbs that peak at 50000 lumens. These are used for plant growth. The sodium bulbs peak in the yellow green (2000 kelvin) and would make for a very UGLY aquarium, but based upon this discussion do you think they might actually be more beneficial to our light lovers?
 
michaeltx

michaeltx

Moderator
Features:
* Excellent colour rendition
* Crisp Blue Hue - 50,000K
* Medium Base.
* Will work on Hellolights 150/175W Electronic ballast.
* A high quality, well made bulb.
Mike
 
rickster

rickster

Member
I also just found this chart....
Light Source lumens 1.0 m2 1.5 m2 2.0 m2 2.5 m2 3.0 m2 3.5 m2
1000W HPS 140000 -- -- 70000 56000 46700 40000 35000
600W HPS 90000 -- 60000 45000 36000 30000 25700 22500
400W HPS 50000 50000 33300 25000 20000 -- -- --
250W HPS 29000 29000 19300 -- -- -- -- --
1000W MH 115000 -- -- 57500 46000 38300 32900 28800
400W MH 40000 40000 26700 20000
This seems to indicate that HPS lamps have a higher LUX (another new acronym that I learned tonite) which measures lumens/meter^2......does anybody use these lamps on aquariums?
 
attml

attml

Active Member
Rickster,
I used 250W purely for an example comparison. I would still rather have 1 - 250w MH bulb than 4 - 65W (260w) PC bulbs over my tank. In that scenario even though you get 10 more watts of PC lighting you still more bang out of the MHs! As far as the color that the bulb burns at (in kelvin) you want to stick with between 6500K and 20000K. Below 6500K you begin to have issues with unwanted algae growth and above 20000K and you have to add a lava lamp and a felt neon Led Zepplin poster to your tank!:)
 
wamp

wamp

Active Member
Thanks for the replies...
So, in your opinion.... 2 250w 20k should do the trick?
Anoyone run this setup without supplemental actinics? I had 3 175 10k and 4 actinic VHO over my 180 but do not want to go that route again.
I have always wanted to run a single light source setup for ease of cost replacment and for a little better electricity consumption.
With a 20k , I am guessing here, I was hoping to have a blue-White tank and still provide the adaquate spectrum for SPS. I know 400w would be better but with the tank size and heat ouput I am a little worried.
Any more advice would be appreciated here....
Golfish,
Are you advising to run 2 diffrent bulbs?
 
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