lumens per gallon?

[endparenthesis]

Would you lighting experts consider lumens per gallon to be a more reliable measurement of lighting levels than watts per gallon? It would have the added benefit of being universal across all the different types of bulb, wouldn't it? And wouldn't it accurately measure smaller setups (like 14 watts for 5.5 gallons) as "low light" even though it would be about 3 watts per gallon? Or is this scale wrought with problems as well?

Where do you think you would define the "levels"? Low light being below 100 lumens per gallon? High light being over 200? Would those numbers work?

Any thoughts?

 

[Lateral Line]

It may well be a more realistic unit, but many lamps do not have the information readily available, (ie. printed on the lamp), and I suspect the majority of fishkeepers probably would understand it even if they did.

I suspect whilst lamps continue to be sold by "Wattage" the "Watts per gallon" business will continue even though, as you correctly point out, the relationship is non linear. One could equally well argue why use gallons when a) there is more then one kind of gallon and B) gallons are not used as units over most of the planet.

I think the spectrum of lamps is also important. There are an awful lot of very expensive fancy spectrum lamps around which in unskilled hands are a poor investment. I also see a lot of relative newbies delighted because they managed to find some lamp with a ridiculously high "temperature" and are disappointed to find out they would have been better off with a lower value.

Tank depth and geometry are also relevent.

 

[Silly me]

Is hard to add to what Lateral Line said, but there is so many values that light are measured. I wouldn't see lumens as a good measurement, even if it does display the amount of light, not what light.

some fancy lights dispay tri colour 20watt T12 1020 lumens
most cool white lights display yellow/green 20Watt T12 1580 lumens
full specrtum display most colours 18Watt T8 1850 lumens

If you were to use a better scale, it would be better the make a reading of a light in PAR versus colour, but almost no light has the PAR value on the side of the box.

If all companys would just stick to the same measurements.. boy.. perfected world...

Also PAR has a higer value in a light if the K are higher