How many watts is what???

[50cal]

I do not know the correct forum for this- admin please move if necessary:

My question is:

When we discuss lighting wattage, is it cumulative? For example, if I have two 13 watt lights operating, am I operating 26 watts, or is it still only 13 watts? That is all the power each fixture is “putting out”.

I had been considering this myself, but recently saw a post on another forum that I now can’t find that claims the latter; that the max output of a single unit is all that you get regardless of the number of units…

I do not believe I have ever read a post on this board that did not “total” the wattage of fixtures for the final wattage figure.

I just wonder if anyone had done any testing, or any of the electrician types out there know.

Thank you.

Craig

 

[Anonymous]

If you have two 13 W light, and you turn both of them on, they will consume 26 watt together. Each bulb is consuming 13 watt, but together, they use 26watt.

 

[Anonymous]

Watts are additive. For instance two 13 watt lights is 26 watts on your tank.

the reason watts are popular is it is much easer to get the watts than the par or lumens and other things. It is also makes sense to me because for a given volumn you can have less top area but more height or more top area but a lower height. So a tall tank needs the same watts but in a smaller area. And therefor the same light in a smaller area or brighter. And therefore can penetrate the water better. But then It has to as the tank is taller and the light has further to travel.

Within a given lighting configuration like say PC actinic, the watts probably generally reflect the light being generated. But outside of that comparison there are great differences in the light output (par or lumens) per watt. And spectrum also. You can not make any valid comparison between, incandescant, NO, MH, PC, haligen, sodium vapor and so on. Of course IMO. You should be comparing the light output (par or lumens) per gallon not watts. But that information is much harder to come by so most just use watts.

 

[Anonymous]

Yah watts can add, but if you use watts per gallon rule *shutter* then yah you can add them. But only the watts the bulb uses if you get a compact fluorescent bulb that says equivilant of 100 watt bulb.. you don't use 100 watts.

 

[Anonymous]

I feel ya sfsuphysics...the watts/gal rule is inaccurate...as said 100W of Power Compact isnt the same as 100W of Normal Output..In fact the Power Compact is more efficient and more "powerful" the same goes on up the ladder with T-5, HO, VHO, MH.

 

[WRASSER]

watts are a gage we use to measure lightng, it is in fact wrong, but for now it is all we have.lordnikon is right, but soon they are coming out with bulbs that are measured in nano-meters. this will help gage lighting for a tank

 

[Anonymous]

Watts equals power consumption. They add.

Louey

 

[RobertoVespucci]

But equal wattage across different bulb types is not necessarily the same light output, even if the bulbs seem the same physically. Some types more efficiently convert electricity to photons. Four 65 watt VHO flourescent bulbs will not be as bright as one 250 watt metal halide bulb.

 

[Anonymous]

Simply Watts is a measure of power, not intensity. but yes doulbing up is doubling power consumption and intensity..

simple addition 2 50W bulbs essentially equals 100W..Now are the same 100W of say NO the same as VHO of 100W? no...

 

[Juck]

watts are a gage we use to measure lightng, it is in fact wrong, but for now it is all we have.lordnikon is right, but soon they are coming out with bulbs that are measured in nano-meters. this will help gage lighting for a tank

Huh? You can get a spectral plot in nanometers for just about any bulb on the market already. Right?

Rating bulbs in Nanometers alone makes no sense at all.