Honestly, would you do MH or T5 over a 20H?

Newreeflady

New member
I am needing ideas for a canopy build for my new 20H, but first I need to make a final decision on the lighting. I am very close to just sticking with T5, but not 100%, and since the fixture I ordered is still on backorder, it's my last chance to reconsider. I haven't done T5 before, but have seen others with good results and coloring.

Thoughts?
angela
 
Even though I'm an MH guy, I'm sure T5s will do the job and are best in this case. It would be tough to fit both MH and actinics over that small a tank, also MH would be a bit overkill and probably have heat issues.
 
I agree with the rest. T5's will work great on that tank. You will have minimal heat issues and you can mix up a few different bulbs to get the color you want.
 
T-5 with individual reflectors. Heres some pics of my old 20H with Nova Extreme 24". It was before they made the SLR type, so it's the old single parabolic reflector:(

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Everything I ever wanted to try in the tank as far as frags and such worked out great. I never lost a frag or had one bleach out. Color was not the best with the stock bulbs, but after i switched them out, it looked great! I chose to go with:

UV-Aquasun 12k
UV-Reef Blue 10k
Current 460nm Actinic
420 Super Actinic (some German brand)

All my frags responded great to the new lights, and they really brought out a lot of colors which were not visible under the stock bulbs, and seemed to make the tank "pop" a little more.

I hope you enjoy your new fixture, and i hope you know all of us on this forum are expecting lots of build/setup pics, and stuff you take as you are going along.
 
My reading indicates is that it is a widely held misconception that MH lamps transfer more heat than equivalent wattage of t-5 lighting. Assuming you used 4 29 watt t-5 lamps (I'm assuming it is only a 24" tank), that is a total of 96 watts. Watts are a unit of electrical power. The energy in a watt of t-5 power is the same as a watt of MH power. Therefore the heat produced will be exactly the same. The perceived difference is that in t-5s, it is distributed over the length of the lamp therefore at any given point it does not feel as hot. With a 20 gallon tank, you could conceivably get away with a 70 watt MH lamp thus actually using less power for roughly equivalent photosynthetic activating response (PAR). Having said that, t-5 may yet be a wise choice since you can configure a lamp combination to suit your needs. I just mentioned this to clarify this misconception.
 
Not to start an argument here but there is a huge difference in the heat output of different devices rated the same wattage. Two devices rated at the same wattage can have different heat outputs. Fluorescent bulbs are more efficient at producing visible light. That means more energy goes into producing visible light and less energy is wasted on heat. That is why a 40W fluorescent bulb produces the same amount of light as a 100W incandescent bulb. The incandescent bulb wastes 60W on heat (electromagnetic radiation in the non-visible range, usually infra-red).

If you have two bulbs rated the same wattage and one is more efficient at producing visible light, the more efficient bulbs will produce more light and less heat. The difference here is the wavelength of electromagnetic radiation. Both bulbs are putting the same amount of energy into the system but they are putting in different forms of energy. A more efficient bulb produces visible light (and some UV) that is a usable source of energy for photosynthesis. A less efficient bulb produces IR light that is not used in photosynthesis but is absorbed by objects and raises their temperature.

So, once again, two 100W lights are putting the same energy into the system but they have different visible light/heat ratios.

Dave
 
I can't argue with a physics professor:) Thanks for the clarification. I stand corrected. Some time ago i read a thread, I believe on the "Advanced Reefkeeping Topics" forum where this point was raised by someone who seemed to know what he/she was talking about (or possibly I misenterpreted the issue) but what you are saying makes absolute sense.
 
<a href=showthread.php?s=&postid=15044521#post15044521 target=_blank>Originally posted</a> by drbronx
I can't argue with a physics professor:) Thanks for the clarification. I stand corrected.

HAHA!!!! I was just about to put this statement on the thread!
 
I can't argue with a physics professor:) Thanks for the clarification. I stand corrected.

Come on. This is the internet. You can argue with anyone you want, its practically encouraged! How do you know he is a physics professor, have you seen him teach? Even if it dose make sense and I think that I just learned something. :D
 
I would go with T5 since MH will produce more heat. Canopy for MH would have to be about 18" tall for MH and on a small tank it doesn't look nice IMO
 
I guess I'll just take your word for now, as all your other forms of "proof" could be easily photoshoped. :)

Back to the OP, Have you thought about leaving the back open to allow for more air flow? You will probably have to deal with more evaporation. I personally love the shimmer of MH but have seen some T5s with LED supplements that create the same effect in which case I would probably go with T5.
 
Thank you! I was so excited to get moved into my new tank when i got it, but now that I look at old pics of my 20, i kinda wish i never got a new one. HAHA I can't ever be happy! I guess I just need to get my new tank grown out that much
 
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