Led bulb par test

So i ran a small trial with this led bulb
I used a hacksaw to remove the bulb
The par reeding was at 190-200 with the bulb attached at 3 inches away
At 3 invhes with the bulb off i was getting a reading of around 1250-1400
Only reason im doing this is because there is a power savings program in my area that gives you leds to save on electrical consumption so they gave me 60 bulbs.
Im thinking of building a small box with a couple of these up-top to start seedling

I'm wiring up an entire 6 tier metal rack with 9w screw in bulbs. For microgreens, seedlings, etc. 9x8 watts per shelf. I'm actually leaving the globes on so I can spray, and don't need as intense of light for micros.

I've been using these lamp holders https://www.walmart.com/ip/50Pcs-4A-E27-Light-Socket-Screw-Bulb-Pendant-Lamp-Holder-Plastic/102523595

And, cheap brand new 12ft extension cords that have SP2 wire. Way more than suitable for the job. Its actually cheaper to buy the cords when they go on sale than an actual roll of lamp wire, and they already have free sealed off plug ends on them too! The wire fits those lamps holders i linked so perfectly too.

Then just rig them up like rope light strings, like 10 bulbs per 12ft extension cord.

Many ways to attach, to a board or frame, using zip ties or wire holders, etc.

Yours are dimmable, that's cool!


You can grow nice buds using the 100w equivalent, over a scrogged canopy. I also make very powerful light fixtures, like 6-800 watts, from the screw in bulbs, for so cheap per watt! I can beat any par meter sheet for any commercial light fixture, with screw in LEDs made by slave labor in china, for a fraction of the price they are asking. Haha

Billytheluther said:

So i ran a small trial with this led bulb
I used a hacksaw to remove the bulb
The par reeding was at 190-200 with the bulb attached at 3 inches away
At 3 invhes with the bulb off i was getting a reading of around 1250-1400
Only reason im doing this is because there is a power savings program in my area that gives you leds to save on electrical consumption so they gave me 60 bulbs.
Im thinking of building a small box with a couple of these up-top to start seedling

Click to expand...

This auto (gg#4) was grown under two four way photography splitters with 2x11w 2700k and 2x11w 6500k globes in each. Total of 88w in a 3x1.6.

They do a pretty good job, especially for autos when you can run 18hrs to make up for lack of par.

I use these. A few bucks off eBay.
They come in 2 up to 7 way.


I made a setup for a mate and ran three four way splitters in a 2x4. The outside two had 56w worth it 3000/4000k and the middle splitter had 44w worth of 2700k/6500k. Had good spread, cost next to nothing and only required one plug. I just mounted them to one big piece of ply and spliced all the power cables together to run off one lamp switch.

Ima rigg something up tomorrow, ill probably use 6 of these anto see if they work for a 2x2

Billytheluther said:

So i ran a small trial with this led bulb
I used a hacksaw to remove the bulb
The par reeding was at 190-200 with the bulb attached at 3 inches away
At 3 invhes with the bulb off i was getting a reading of around 1250-1400
Only reason im doing this is because there is a power savings program in my area that gives you leds to save on electrical consumption so they gave me 60 bulbs.
Im thinking of building a small box with a couple of these up-top to start seedling

Click to expand...

Send them a request for a Gavita lol sell them on efficiency lol

Billytheluther said:

The par reeding was at 190-200 with the bulb attached at 3 inches away

Click to expand...

please? Dont tell me you didnt cut off the diffuser? First thing to do. i measured 700-800 PPFD 10cm, and 250 20cm straight under the bulb. was a 1521lumen bulb, 13 watt.

With 13watt/1521 lumen bulbs you reach about 1,8 umol/J with cut off diffuser. These bulbs have about 130 lumen/watt. I was also planing to build a light like that. There are even some highpowered and more efficient bulbs from Osram Parathom, i think 160 lumen/watt. 16 watt für 2500 lumen or something like that. Most efficient ones i found. Everything more efficient is filament-stuff which doesnt work to well because the light spreads in all directions.

mannitu77 said:

please? Dont tell me you didnt cut off the diffuser? First thing to do. i measured 700-800 PPFD 10cm, and 250 20cm straight under the bulb. was a 1521lumen bulb, 13 watt.

With 13watt/1521 lumen bulbs you reach about 1,8 umol/J with cut off diffuser. These bulbs have about 130 lumen/watt. I was also planing to build a light like that. There are even some highpowered and more efficient bulbs from Osram Parathom, i think 160 lumen/watt. 16 watt für 2500 lumen or something like that. Most efficient ones i found. Everything more efficient is filament-stuff which doesnt work to well because the light spreads in all directions.

Click to expand...

why do you care about lumens/watt? What quantum meter were u suing to measure PPFD?

Drasik said:

why do you care about lumens/watt? What quantum meter were u suing to measure PPFD?

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Some people worry about the heat being produced for a given amount light. A more efficient light will produce far more light while putting out less heat. What's not to like?

If you have a light that puts out 115lm/W and one that puts out 230lm/W like a 301b, it will literally take twice the power and heat to produce the same amount of light for the less efficient diodes.

I'm planning to wire up an entire 45' semi dry van trailer full of 4 tier hydroponic microgreen growing racks, probably 50 amps worth of screw in LED bulbs! Truck loads of them.

I guess i'll be the first guy crazy enough to use that many screw in bulbs, if not owning thousands of them as a consumer at one time.

I'll have so many, that when they flicker out I'll just return the boxes to walmart or the dollar store with the burned out ones (it's BS that they don't last 9-18 years as advertised!), and get a one up on them, so I'll pretty much never have to pay for bulbs again, (for 5-10 years at least dang it!)

Its gonna be lit!

I'll be spending maybe 20-25 cents per watt (or less with bulk deals on sockets, wires, and bulbs), compared to dollars for commercial fixtures.

VincenzioVonHook said:

Some people worry about the heat being produced for a given amount light. A more efficient light will produce far more light while putting out less heat. What's not to like?

If you have a light that puts out 115lm/W and one that puts out 230lm/W like a 301b, it will literally take twice the power and heat to produce the same amount of light for the less efficient diodes.

Click to expand...

But isn't there another factor that can effect ppf output at a given wattage besides lm/w rating?

VincenzioVonHook said:

Some people worry about the heat being produced for a given amount light. A more efficient light will produce far more light while putting out less heat. What's not to like?

If you have a light that puts out 115lm/W and one that puts out 230lm/W like a 301b, it will literally take twice the power and heat to produce the same amount of light for the less efficient diodes.

Click to expand...

My questions was not about using LEDs, more efficacy is better than fugative heat.

Plants don't care about lumens(how bright something is) they care about photons how much energy in available to drive photosynthesis. So wouldn't a better measure of be your efficacy and knowing your PPF? 230lm/w doesn't accurately tell me anything about how much energy/power I have available to give to my plants.