Estimating PPFD from PAR?

[newbie2323]

I'm trying to work out the conversion factor for converting (estimate, of course) from PAR to PPFD on my setup. Running the light below that has two BridgeLux 3000K 80 CRI COBs @ 50w each and 24 6000K LEDs @ 5w each. https://www.amazon.com/gp/product/B079C2YF8F

What's the math?

 

[Rocket Soul]

PAR and ppfd is (generally speaking) the same thing.
There are some ways of calculations in the math behind thread but i i nt think they will apply to well to this case. Just ask the seller to provide some ppfd measurements. They should if they wabt to sell it. But the light doesnt doesnt look too good, maybe try something different. 99% of amazon lights are crappy.

 

[ZHChris]

In fact it should be PPF or YPF not PAR,You should ask them how many umol/j ,like 2.5umol/j *Operating power 100W,PPF should be 250umol/s

 

[newbie2323]

Thanks guys - I misspoke. Mean to say LUX to PPFD... They've provided a PPFD map. I just picked up a Lux meter and wanted to compare their claimed values to my measurements. Just need the conversion factor (0.016 ish) from lux to par/ppfd

 

[Moflow]

This might help you
Here's a guestamation.
There's no 4500K so try 4000k. That should get you a ~ ball park figuire
Other options in the scroll down menu too
https://www.waveformlighting.com/horticulture/convert-lumens-to-ppf-online-calculator

Also
https://www.rollitup.org/t/in-need-of-a-par-multiplier-for-qb-setup.976518/#post-14491207

 

[Moflow]

33900 lumens = 604 umols... 4000K led

 

[newbie2323]

https://www.rollitup.org/t/in-need-of-a-par-multiplier-for-qb-setup.976518/#post-14491207

Awesome! Thanks man! I'm coming up with ~ 0.0145 for the cobs (1/69 from that thread) and ~ 0.0887 for the 5w LEDs (reverse engineering the calculator at the other link)

I think I'll just measure the lux of each separately rather than take an average.

 

[newbie2323]

But the light doesnt doesnt look too good, maybe try something different

Can you elaborate? My plant seems to like it so far, but this is my first grow so what do I know. I guess I won't know for sure until harvest. What would you recommend for a single plant in a 2x2 tent?

 

[Rocket Soul]

If it works for you and your happy with it just go for it. General buying advice:
- suspect anything on amazon and dont believe the reviews.
- suspect any light that doesnt list their components in details (brand name and wattage is not enough). Demand details on power supply
- demand a ppf/w from an independent lab
- lights that use optics or lenses are usually not great as they will reduce total light levels.

A lot of people around here use boards with midpower diodes, for example horticulture lighting group. Check out their R-Spec boards if you like.

 

[Ryante55]

Thanks guys - I misspoke. Mean to say LUX to PPFD... They've provided a PPFD map. I just picked up a Lux meter and wanted to compare their claimed values to my measurements. Just need the conversion factor (0.016 ish) from lux to par/ppfd

View attachment 4379258

Looking at that ppfd map that light covers a 1x1 space with veg numbers

Edit wait I didn't notice that said 4' looks like that light covers a 2x2 with veg numbers

 

[newbie2323]

If it works for you and your happy with it just go for it. General buying advice:
- suspect anything on amazon and dont dont be the reviews.
- suspect any light that doesnt list their components in details (brand name and wattage is not enough). Demand details on power supply
- demand a ppf/w from an independent lad
- lights that use optics or lenses are usually not great as they will reduce total light levels.

A lot of people around here use boards with midpower diodes, for example horticulture lighting group. Check out their R-Spec boards if you like.

Appreciate your input! Now I've got a bug to build my own.