MH efficiency

Hey guys, this has probably been brought up alot but I can't find it in search. I was thinking about adding Metal Halides to my tank. I am just running 3 60" VHO off an ice cap ballast right now(super actinic and 2 white actinic). Which is fine but I'd like to have the ability to keep just about anything and it is a 30" deep tank so MH seems the way to go. Question is. How efficient are they? It seems like that kind of wattage would drain alot of power. Are there some that are more efficient than others? I already have a $500 electric bill..(heated pool doesnt help). I don't need that to skyrocket any more. If it isn't an extreme amount of an increase in power usage then I'd do it...Thanks!

 

Let's put it this way. I don't think MH's will ever get the Energy Star seal or rating LOL and remember. watts is watts it's all the same as energy consumption is concerned. the thing that makes mh cost more ion the long run is the heat that they produce. You will either have to run fans, chiller or a/c vent right over and then inturn your a/c has to work harder to get rid of the heat. In a big room it might not be that big of a deal, but in smaller rooms you will notice the heat.

 

For a 30" tank that you want to grow anything in there is not much left to debate about it. You should talk to people on both side before making your decision. The lights do not put off that much heat as I run 3 400w MH's and 1 small 6" vent outside for the humidity and heat.
I hate getting into these light debates because everyone thinks they have read the right stuff and their light choice is best. If you are going to keep easy soft corals then go with the cheap lights, if you are going to keep Acro's and clams then MH's are your answer.

 

Mh's and t5's are alot better then vho's and cp in terms of efficency
t'5 are slightly more efficient then mh's
the advantages of t5's is the bulbs lose very little output over time
but t5's are only good around to 20"
i would probably get mh's if i was you
with mh's the efficency is dependent on the quality of the ballast and bulbs.
which is why you don't want to go cheap

 

I do run MH, so I will tell you my experience.
First off, not to directly contradict gras, butttt.... The energy usage is not the same for every type of light. Giving 300 watts purely as an example, 300 watts of T5 will use less energy than 300 watts of MH. Its all about the power that the particular light has to draw in order to produce the 300 watts. Thats were the term "efficiency" comes in. MH's are not efficient.
How much it really uses up depends on a lot of factors. The bulbs and ballasts being the biggest.
The best way to figure out what its going to be is to get the energy usage of the particular light you want and figure that with the current cost of electricity were you are.

 

It's going to come down to the difference in wattage. You can figure out exactly how much more it will cost if you know how much you pay per kilowatt hour.

Say you have 200 watts of lights running for 15 hours a day

200 x 15 = 3000 watts/day
3000 x 30(days/month) = 90,000 watts/month
90,000/1000 = 90 kilowatts per month

then you multiply your kw by how much you pay for it
90kw x $.10 (gotta find your price per kw hour) = $9 per month

if you jump up to 400 watts it will double, etc.

 

The big question I have can you run 220, if so MH is the way to go.

 

I run my MH's, exhaust fans, 2 HammerHead pumps and a O3 Generator all off of 220v. Saves money in the long run.

 

Thats the problem in figuring it, though. A 400W Light does NOT draw exactly 400w of electricity. It draws more. The only way to figure it is to find out exactly how much the light draws.

 

When you have a fixture that claims X watts, you have to also consider that (X= Input power). The true power you are using due to inefficiencies such as (Y=magnetic/copper loss) is equal to X+Y. For Example:

Metal Halides:
Claim:
250w puts out 16500 lumens
Actual:
295w total due to inefficiencies (Y) puts out 16500 lumens

T5s
Claim:
54w puts out 5000 lumens
Actual:
62w total due to inefficiencies (Y) puts out 5000 lumens

What does this mean?

(2) 250 watt Metal Halides
you burn 590 watts to get 33000 Lumens with Metal Halides

(6) 54 watt T5s
you burn 372 watts to get 30000 lumens with T5s
All this Data is gathered from the Sylvania + GE 2006 catalogs so you can find out for your own which you want better.
There is also things that contribute to lumen gains/loss, here they are in order of most impact
reflector design
Height it is from top of tank
Y factor
Operating temp of lamp
age of lamp
-baytran7


that is about it. now you have to take into account the depth of your tank issue, you can keep anything in your tank with t5's as long as it is 10 inches up so only 20 inches from the light.
with halides you can keep anything all the way to the bottom.

there you go pack, how much the fixtures actually draw. now this number vary upon the types of ballast and bulbs you get for either.

edit: when thinking about the differences in wattages keep in mind that the difference only adds up to about the amount of energy it take to run 2 regular light bulbs.

i did the math 600 watts of halide lighting would cost me around 14 dollars a month. if i used the t5 i would save 5 dollars.