The Reef Tank banner

Wattage / Efficiency / Long Term Lighting Costs

5K views 5 replies 2 participants last post by  geedoug 
#1 ·
This is sort of a continuation of an earlier thread, but a change in direction: http://www.thereeftank.com/ubb/Forum1/HTML/001811.html

In the earlier thread, I asked what was the difference of 250watts of 6500k PC light vs. MH light vs. VHO light, etc. I see now that I worded that wrong. Part of the hype surrounding PC lights is the fact that they are suppossed to be so much more efficient. Then I see something on a website about Icecap ballasts running 440 watts of lights while using 270watts of electricity.

Then I read that watts are useless and that MH lights of equal wattage put out more PAR, which seems to be the real test of light output. Meanwhile I measure the cost of lowcost PC's via Ahsupply and read about low cost Iwasaki MH (apparently MV) bulbs, and I read about people raving about how VHO light makes everything look.

I now realize what I really want to know. First, has anyone measured the PAR values of various types and wattages of lighting?

And the grand-daddy of all of my questions...
What source of lighting is truly the most efficient in terms of PAR output compared to electricity used ?
How about PAR output compared to initial cost of the lighting setup ?

To expound a bit... let's say for example that Mr. Icecap vendor, I think it was ChampionLighting, but that's beside the point, is right and an Icecap ballast and 440 watts of VHO burns 270 watts of electricity. How does the PAR of that compare to say... one 250watt Iwaski bulb (assuming that it burns 250watts of electricity)... or to five 55watt PC's (again assuming that's 275watts of electricity used).

I think once this was known, compared to the differences in initial cost and bulb replacement, the only thing left would be magical lighting qualities like this "sparkling effect" I keep reading about MH's...

If you really interested in the subject, and haven't read it already, there is an interesting similiar thread about the cost of ballasts and other hardware at: http://www.reefcentral.com/vbulletin/showthread.php?threadid=12169
 
See less See more
#2 ·
Ok, here goes a try at what I believe to be substantially correct. Some EE might be able to argue some nits, but I think for most of us this will apply.

First, 250 watts is 250 watts. If the heat output of two different bulbs are measured at 250 watts each, than each bulb is consuming the same amount of energy. Now having said that, there are differences in how the electricity is applied to the filament of the bulb. In the simplest case, a standard light bulb, then the electricity is routed directly to the filament, and therefore no other electricity is consumed except for the 250w being dissipated by the filament.

So now we need to consider how we power that bulb. In the case of metal halide, we use a ballast. Ballasts basically perform two functions, 1. Provide the starting kick, and 2, Limit the current to the proper value for the bulb/tube you are using. Since ballasts perform a function, they themselves dissipate power or watts, and must be included in the total cost to operate.

I believe it is the ballast (somebody correct me if I'm wrong) where we can save operating cost by selecting a different type. Basically there are three types of ballasts, tar, cap and coil, and electronic. The are listed in the order of efficiency, from lowest to highest. So ignoring any neat design of a certain electronic ballast for the moment, it's simply more efficient to perform the function of a ballast via electronic means, than by either of the other two methods. And more efficient means less power consumed, which means less heat dissipation, which means cheaper to operate.

Now some electronic ballasts make claims of running the bulb more efficiently, and therefore running the bulb at a lower wattage, cooler, to produce the same amount of light for less electricity used. While I'm sure this is true, it begs the question that if the bulb which is designed to burn at say 250 watts in order to produce a color temperature of 6500 degrees kelvin, what is the color temperature of the bulb on one of these new ballasts? Perhaps it's very close, but perhaps not...another discussion I think.

Having said all that, I think it's safe to say selecting an electronic ballast for use with any type of bulb will save you on operating costs.

The next thing to consider is replacement cost and frequency. I believe that the hands down winner in the high intensity class is MH. For example a $69 250w Iwasaki MH bulb will last close to 18-24 months before it's intensity and color spectrum have changed enough to warrant replacement. A $40 96w CF bulb will need to be replaced at a frequency no longer than every 9 months. I don't have any experience with VHO but I've heard 6-9 months on those also.

Hmm, this has gotten a bit long winded, lets see what comments what I've said elicits.

------------------
Bill Esposito
bespo@cereal.mv.com
JAqua for the AquaController 2
http://cereal.mv.com/jaqua.html
My Reef Page
http://cereal.mv.com/reef
The box said "Use Win 95 or better", I chose better so I run OS/2!
 
G
#3 ·
Bill I agree with most of that, but in my experience VHO will go a year on IC e ballast without the hair algae plagues reported by others when the spectrum shifts. The manufacturer claims around 18 months, but I think a year is ok. I ran a pair of Corallife actinis till they burned out at 18 months with no noticable side effects. One of these days I need to get a lux meter and actually tract the output, though I dont know of cheap spectrum analyzers



------------------
I thought I was me, but we were wrong
email: geeflipr@internetcds.com
 
G
#4 ·
Interesting questions. I have seen a few articles over tha last few years that compare various MH bulbs in terms of PAR and efficiency, but unfortunatly nothing that runs the whole gamut testing the bulbs and ballasts of the popular equipment. I am not an electrical engineer so bear with me if I express things in the wrong terms.
In order to arrive at any meaningful conclusions you would need samples of the various bulbs and ballasts available in the hobby. My thinking is that then you would need to measure lumens at a standardized distance, figure out the PAR values for each setup, power consumption of each bulb/ballast combination then compare typical costs to aquire the lighting in question. At that point I think you could begin to make a reasonable decision regarding cost/benefit ratios. OK now that you have figured that much out the two other glaring factors that must be addressed. First off and foremost, what are the light demands of the organisms you plan to keep. Secondly what is the distance the light has to travel, water depth, refractive loss,etc. I think those are the basic factors to consider. I know this is simplistic for a complex subject, but I think you get the point.
My Personal take on the subject, its hard to beat the PC setup from AHS for a tank smaller than 30g.These will support most of the so called low light, hardy beginer corals. Someone wanting to do a small tank with SPS or Clams can set up with MH for $200 or less if you shop right. I think Icecap VHO is a good choice on 4 ft tanks in the popular sizes. Again it will support the easy corals and can form the basis of a more intene lighting system by supplementing Metal Halide lighting as ones choice of creatures changes over time. Deeper tanks will benefit from MH lighting and while clams and sps havew been kept successfully by some using PC or VHO, so many SPS lovers are changing to mega watt MH and reprting better results, there must be something to it. I doubt most people scrapping their existing spendy lighting to upgrade just like spending money;-)
One thing to keep in mind, there have been at least a few posts that state, according to measurement taken from wild reefs, the light levels an hour after sunrise exceed the levels of light in an aquarium lit by MH bulbs(175 was referenced as I recall) If anyonew happens to have that refernce bookmarked please post it.
It seems to me recent trends in high lighting levels tends to dispell old myths that too much light will "nuke" your tank. Tanks running well over 10 watts/gal arent that uncommon and as long as the heat buildup
and animal placement are addressed, its pretty hard to over light a tank,HTH

------------------
I thought I was me, but we were wrong
email: geeflipr@internetcds.com
 
#5 ·
You know, I think I'm on the verge of realizing that at this point in time it would be cheaper to use VHO's than PC's. Roughly speaking, I think I can get an IceCap, the rest of the fittings and four bulbs for about say $350. Even at Ahsupply.com, I believe I'm looking at $480 for eight 55 watt bulbs. And more expensive bulb replacement. But I have to wonder how even those two setups would compare on my tank. If the VHO setup truly only used 270watts of electricity and had roughly the same PAR as the PC's, VHO would win by a landslide. Cheaper initial cost, bulb replacement and electrical costs. But the question here is... would they put out the same amount of usable light as PC's ?

And as an aside, how does water depth/light penetration factor in ? I have a 120 gallon tank, so it's a bit deep.

(I haven't forgotten about MH, just seems logical to determine a flor winner to compare it against)
 
G
#6 ·
Look into the 96watt PC from AHS, that should cut the cost some. One of the probs with PC is the limited availability of true actinic.
If thats important VHO is definatly easier to find. I havent seen any data on lumen or lux output between the 2 types but I would guess they are gonna be close. FWIW the human eye is really the worst judge of lighting, our brains selectivly filter it to please us.
I use VHO so I am biased but I think its a cheaper setup to maintain on a 4' tank. Aa 120 thats 2' deep is gonna need more lighting to support anything other than soft corals. MH halides retains more intensity at tha bottom. You can always add to later, just keep that in mind when building a canopy

------------------
I thought I was me, but we were wrong
email: geeflipr@internetcds.com
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top