James77
Team RC
Slathrum, here is a good thread concerning the subject:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1330449&perpage=25&highlight=watt heat&pagenumber=1
Halides vs. T5's
- Thread starter fender4string
- Start date
Slathrum, here is a good thread concerning the subject:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1330449&perpage=25&highlight=watt heat&pagenumber=1
slathrum
Member
Well, I guess our lights defy the laws of physics then if all of our light energy is equally converted into heat. Energy doesn't just come out of nowhere. If energy is being used to create light, then it is not creating heat. The more efficient a light setup is, the more light it will create per watt used whether it is T5 or MH.
mightyevil
New member
So then on my 72''x24''x24'' I should go with MH?
should I do MH only or supplement with actinics?
What do I use? Icecap ballast? what type bulb? where can I get them for less money?
should I do MH only or supplement with actinics?
What do I use? Icecap ballast? what type bulb? where can I get them for less money?
ReefEnabler
Premium Member
I used to have (2) 250w and (1) 400w MH on my 72 x 24 x 30" tank. Lumenmax Elite reflectors. ~8" above water.
I had really intense bright spots under the reflectors (700-800 PAR 5" below water), but still had very poor dark spots between the reflectors (ie, there were places in the tank 5" below the water with 700 PAR, and also places with ~150 PAR).
I was frustrated with the dim spots so recently switched to 9 x 80w T5s overdriven on 3 icecap 660 ballasts.
I have almost the same intensity of the old 'hotspots', about 80%, but none of the dim spots. And I'm actually getting MORE PAR at the bottom of the tank in most areas. So the notion that T5s do not penetrate as deeply as MH is simply a myth.
I gladly accept some loss of hotspots for a much more even distribution and less shadows, better coral branch coverage.
Lumenarc minis would have given better spread than the Lumenmax Elites, but they're a bit too big for my canopy, and they're much less intense than the lumenmax elites anyways, so I'd have lost PAR still.
I had really intense bright spots under the reflectors (700-800 PAR 5" below water), but still had very poor dark spots between the reflectors (ie, there were places in the tank 5" below the water with 700 PAR, and also places with ~150 PAR).
I was frustrated with the dim spots so recently switched to 9 x 80w T5s overdriven on 3 icecap 660 ballasts.
I have almost the same intensity of the old 'hotspots', about 80%, but none of the dim spots. And I'm actually getting MORE PAR at the bottom of the tank in most areas. So the notion that T5s do not penetrate as deeply as MH is simply a myth.
I gladly accept some loss of hotspots for a much more even distribution and less shadows, better coral branch coverage.
Lumenarc minis would have given better spread than the Lumenmax Elites, but they're a bit too big for my canopy, and they're much less intense than the lumenmax elites anyways, so I'd have lost PAR still.
James77
Team RC
Energy also just does not disappear, either. Energy cannot be created or destroyed. When the light produced strikes something, be it sand, rock, coral, the wall, whatever- it will be turned to heat or used (by coral, i.e.). If it is put to use, that will become heat.
It is the same for a 100 watt water pump and 100 watt heater. Both will impart the same heat, 100 watts, into the water.
ReefEnabler
Premium Member
It is true a 100w pump will produce exactly the same amount of heat as a 100w heater; however, there is a difference between an external (air cooled) and submersible pump.
The air cooled pump will give off more heat to the air and thus the room. This may not be an overall energy savings (ie, hot air means house AC cylces on more often), but it might be easier to remove the heat via exhaust to outside or something.
In the same way T5s and MH do produce the same heat watt for watt. But T5s have a greater surface area for fans to blow across and it might be possible to extract more heat via ventillation. Your mileage may vary. But there is absolutely NO doubt that a watt is a watt and the luminous efficacy has absolutely nothing to do with it. The light itself still generates heat as others pointed out.
The air cooled pump will give off more heat to the air and thus the room. This may not be an overall energy savings (ie, hot air means house AC cylces on more often), but it might be easier to remove the heat via exhaust to outside or something.
In the same way T5s and MH do produce the same heat watt for watt. But T5s have a greater surface area for fans to blow across and it might be possible to extract more heat via ventillation. Your mileage may vary. But there is absolutely NO doubt that a watt is a watt and the luminous efficacy has absolutely nothing to do with it. The light itself still generates heat as others pointed out.
drparker
Premium Member
The only difference will be the efficiency of the ballast, a 90% efficient ballast will pull about 445 watts to drive 400 watts of light and will turn the extra 45 watts directly into heat. So placement of the ballast and it's efficiency will also effect heat transfer and cooling design.
ReefEnabler
Premium Member
good point.... a kill-a-watt is probably the only way to know the true amount of power being drawn. you can't just go by the raw wattage specs.
gooyferret
New member
What is really funny about this post is back in 2003...they had this same debate! When t5's HO first came out people were comparing them back then....only difference is that it was not vs MH but against PC's and VHO! haha Im old i know! but back in the day that was the new thing t5's and they have finally caught on to the aquarium.
Back then i had a company that was will to make me a complete hood system with 8 - t5's for $300 and now i wish i would have done it! Instead I opted for the 250watt MH that costed me $600 for retrofits. This debate will never end, MH have been through the test of time and are trusted even with alot of heat.
Wattage makes no difference with the lighting (except cost to run) its the way its projected and intensity of light from watts being used. They could come out with a 1watt bulb and produce the same intensity of light that either make some day. SPS can be kept with even VHO lighting (which i really like the look of).
MH does have a very simple advantage over t5's or any other fluoresent bulb though......the reflector. The reflector is getting better and better for the MH's and not much can really be done with the t5's.
Anyways this is getting too long of a post! haha. Just thought i would through out some old advice. And im glad to see t5's in the market, but since i have the cost into my MH already i will stick with them for now......
Back then i had a company that was will to make me a complete hood system with 8 - t5's for $300 and now i wish i would have done it! Instead I opted for the 250watt MH that costed me $600 for retrofits. This debate will never end, MH have been through the test of time and are trusted even with alot of heat.
Wattage makes no difference with the lighting (except cost to run) its the way its projected and intensity of light from watts being used. They could come out with a 1watt bulb and produce the same intensity of light that either make some day. SPS can be kept with even VHO lighting (which i really like the look of).
MH does have a very simple advantage over t5's or any other fluoresent bulb though......the reflector. The reflector is getting better and better for the MH's and not much can really be done with the t5's.
Anyways this is getting too long of a post! haha. Just thought i would through out some old advice. And im glad to see t5's in the market, but since i have the cost into my MH already i will stick with them for now......
slathrum
Member
Oh well, I guess I'm just too stubborn or ignorant to buy into this. Even the pump analogy does not make sense. The majority of the energy used by a pump is used by transferring it into water current. Try heating your tank solely with water pumps and I think you'll find you need quite a bit more pump wattage than you would heater wattage. Eventually, that energy will disperse and be no more. Energy is certainly not infinite in that way of thinking. Lighting is no different, except for that some of the electrical energy used to produce light produces radiant heat in the water.
gooyferret
New member
Yes they have come along also but there is only so much you can do with single line reflector.. Trust me im not dissing on either of them, I knew eventually t5's would get more popular just didnt think it would take 6 years! LOL
James77
Team RC
Throw a 50 watt pump and a 50 watt heater in their own 5 gallon buckets and see what happens. Uncovered, the one with the pump will be cooler as it is losing its heat/energy to evaporation- it will also evaporate faster due to the surface agitation. All of the pumps watts will be converted into heat in someway. Feel any submersible pump after it is running- they get very warm. The friction from the water hitting itself will recapture the energy that was used to pump.
Throw lids on both the buckets, and they will heat identically. All the energy/heat, except for the heat lost through the walls of the bucket, will remain in the bucket. It is a simple enough experiment to try- see what happens.
If you haven't please read the thread I linked above- it covers this all extensively, takes no more than 10 minutes to read.
fender4string
New member
I haven't checked this thread in just under a week or so-I thought it would have died by now 
.
At least based on the information in this thread I feel that I pretty much can't go wrong.
. At least based on the information in this thread I feel that I pretty much can't go wrong.
Tony Romano
Member
maybe......LOL!
gooyferret
New member
You can never go wrong just buy what makes you happy! As for the "debate" its still on and will be till the end of time! AMEN! LOL
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