Lumens are they Cumulative?


Question - Not a super electrician here…know just enough to screw a light bulb in. Are Lumens cumulative? As in if you have ‘two’ CFL bulbs at ‘1000’ Lumens apiece does that equal ‘2000’ Lumens?
Thank you. John C.


I would say yes, because more wattage the lumens increase as well, inn other behalf I wanna say no only wattage adds up.
@MacGyverStoner, what’s your opinion, thanks


I’m using three cfl 150 and small t5


No lumens don’t add up. Lumens is how bright they are. If ones 2000 then that’s it. You can increase your lumens very little with a hood or reflective material. Watts add up an go along with lumens. Most the time…more watts the brighter/ more lumens you’ll have. I wouldn’t worry about lumens so much. Oops tagged wrong person lol also Kelvin are important. 2700k for flower/ more yellow ish. 5000k for veg/ more blue ish. This is for cfls … I know nothing about leds or halide. But should all be the same. I was told er read on here 50watts per 1 sqaure foot. I’m over a 100watts actual use in mine.

Hope that helps.


Good view i like the 4 way splitting ballast first time i seen that, I think lol


Just did that other day When i got that other bulb. The roasting pan for hood was to small. Lol so i put tin foil on roof of that chamber. .


Haha nice that’s a great way to do it, looks like a tin pie sheet lol


John C - It appears there is general confusion in concern to lumens being cumulative. Your post piqued my interest and I asked my brother who has a Doctorate in high energy physics- he says they ‘are’ cumulative? I understand that lumens concerns the temp or brightness of the bulb… Ok, great…Mmmmmm can anyone talk about “Kelvins”? Am I opening up another can of worms - would anyone like to address that? :skull_crossbones:


Yes I will. @voodoodoll, Kelvins are what you use to determine lights brightness and color, for instance a daylight cfl bulb is 5500-6,500kelvins that’s blue spectrum, around 400-460 nanometers of light. A flowering bulb is supposed to be 25-2700Kelvin which is more orange and red spectrum around 680-760 nanometers of light


:skull: Ah, we have a genius in our midst! Thank you Majiktoker.


Any time my friend


I’m sorry but adding lumens is a waste of time. It takes 3 times as much to notice with your naked eye. My 900 lumens bulb is not making my 2700 lumens bulb brighten the room more. The 2700 over powers the brightness of the 900. It doesn’t add up. Yes it spreads the light out farther but doesn’t increase the lumens enough to make it feasible to explain to people yes you can.
Kelvin now that’s interesting stuff, different light spectrums and how they effect plants and people.


Thank you JJ for your input - My question was posed as a “Beginner” (and out of my own natural curiosity) - in order that I had performed proper research on the subject.


this chart points to what I had just typed lol but I converted Kelvin to nanometer for you so that’s done lol way people understand a little more cause nanometers is used for led spectrum vs Kelvin for hid lights


Thank you though cause this further helps them understand the “nanometers” and had I woulda thought about that I would have posted it up lol


Buddy you are a pleathera of knowledge!! I don’t know that much about nanometers so i posted it. I learned by watching you!! Hahaha :grinning:
More info we all have the better.
You’ll welcome.


Here’s a good way to look at it, a normal 400watt hps bulb is 50,000 lumens and is 2700 Kelvin, a super hps 1000watt bulb is 145,000 lumens and is 2500 kelvin. The hps puts out more of a yellow orange spectrum, and the super hps puts off more of a reddish orange spectrum, more red than orange though.

So if I’m not mistaken the regular hps bulb would put off right around 610-650 nanometers (nm) of light and the super hps would be putting off around 610-675 nanometers (nm) of light, and for plants to be able to do the growing persay in vegitative than they need the blue spectrum which puts off chlorophyll B and A in the plants and flowering the reddish orange or yellow orange color puts off the chlorophyll A and B in the plants and the more light they get the more chlorophyll can be processed and the plants can grow :smile: it’s all science lol, more specifically botany


It appears we have two geniuses in the room. I’m overwhelmed! :thumbsup:


Are you new here@voodoodoll, if so welcome to ilgm their are great support members that will offer great help, you came to the right spot and happy growings to you :smile:


We’re can I buy a light fixture like that in your photo