GPPW -vs- PPFD

[Rahz]

The purpose of this thread is to collect data to help establish how phototropic efficiency at various light intensities affect yield. Basically I want to know if the GPW generally goes up as light intensity goes down, what the best case scenario is and at what point that trend begins to break down. I am asking anyone who is willing to submit results. It won't take a whole pile of data to establish meaningful results but since it's not a very scientific test it will take more than a few.

If you can tabulate PPFD that's great but with the proper information I can work that out myself and would probably be more accurate that way. So for the purpose of keeping things simple for me (and you) the following lights are allowable: HPS, T5 CFL, Vero 18/29 (specify whether version 1 or 2), CXA 3070, CXB 3070, CXA 3590, CXB 3590, any others if you can provide radiometric efficiency, or lumens from a -white- light source.

If you would like to contribute please provide the following:

-Light type and output wattage
Examples: 600w HPS, 8 CXB3590 at 1.4 amps (400 watts), 400 watt T5
-Space used
-soil or hydro
-Yield

I will let this thread simmer for a couple months and graph the results at some point.

Example contribution:
23 Vero 18v1 at 1.05 amps
18 square feet
hydro
864 g

I convert the information:
252 Par watts
734 PPFD
Therefore 734 PPFD produces 3.43 grams per par watt in hydro

Enough of these data points and I can graph yield expectations based on light intensity. Yay!

 

[Stephenj37826]

The purpose of this thread is to collect data to help establish how phototropic efficiency at various light intensities affect yield. Basically I want to know if the GPW generally goes up as light intensity goes down, what the best case scenario is and at what point that trend begins to break down. I am asking anyone who is willing to submit results. It won't take a whole pile of data to establish meaningful results but since it's not a very scientific test it will take more than a few.

If you can tabulate PPFD that's great but with the proper information I can work that out myself and would probably be more accurate that way. So for the purpose of keeping things simple for me (and you) the following lights are allowable: HPS, T5 CFL, Vero 18/29 (specify whether version 1 or 2), CXA 3070, CXB 3070, CXA 3590, CXB 3590, any others if you can provide radiometric efficiency, or lumens from a -white- light source.

If you would like to contribute please provide the following:

-Light type and output wattage
Examples: 600w HPS, 8 CXB3590 at 1.4 amps (400 watts), 400 watt T5
-Space used
-soil or hydro
-Yield

I will let this thread simmer for a couple months and graph the results at some point.

Example contribution:
23 Vero 18v1 at 1.05 amps
18 square feet
hydro
864 g

I convert the information:
252 Par watts
734 PPFD
Therefore 734 PPFD produces 3.43 grams per par watt in hydro

Enough of these data points and I can graph yield expectations based on light intensity. Yay!

I've got my shoes off so I'm ready to do some figuren lmao. Great idea. I love it. I can't wait to see the results. My bet is on 600-800 PPFD as the biggest gpw producer.

 

[alesh]

Interesting. But I'd guess that you'd get most gpw from low PPFD, like 200-400.

I convert the information:
252 Par watts
734 PPFD
Therefore 734 PPFD produces 3.43 grams per par watt in hydro

I think that this would be more appropriate

252 Par watts
734 PPFD
Therefore 734 PPFD produces 3.43 grams per par watt with this strain in my hydro setup.

 

[cdgmoney250]

What if we used [Grams/ Square Foot -vs- PPFD] as a matrix to determine how much light is needed to achieve certain yield ranges?

 

[alesh]

What if we used [Grams/ Square Foot -vs- PPFD] as a matrix to determine how much light is needed to achieve certain yield ranges?

That's basically the same as gram per par watt.

 

[doz]

400w CXB3070 AB 3000k @ 36v ~ 1.4a
10 Sq Ft (not optimal, 2'x5' space)
Soil (2 parts FFOF, 1 part FFLW)
488g

 

[cdgmoney250]

That's basically the same as gram per par watt.

I think it would be easier for most people to understand, as it's more relative to the growing space.

 

[puffenuff]

Why are you not including strain details?

 

[Abiqua]

Grams per KWH? as metric.....as suggested by GG way way way back

Personally I am fed up with the infinite variables [it seems] of just GPW.....

 

[Rahz]

Why are you not including strain details?

I could but I figure things will average out. I'm more interested in the shape of the graph than an exact metric, if that makes sense.

 

[Rahz]

Grams per KWH? as metric.....as suggested by GG way way way back

Personally I am fed up with the infinite variables [it seems] of just GPW.....

That would be more accurate but it's easier for people to provide data this way.

 

[Abiqua]

That would be more accurate but it's easier for people to provide data this way.

Totally agree, but are we looking for easier or more accurate

 

[Rahz]

What if we used [Grams/ Square Foot -vs- PPFD] as a matrix to determine how much light is needed to achieve certain yield ranges?

That would produce an interesting result and the data will be there to examine it but it would be a different graph wouldn't it? G/sqft -vs- PPFD would be similar but perhaps variate from the phototropic efficiency -vs- PPFD chart. Gppw -vs- PPFD could be mostly flat and peak at 600, or 200, and that's what I'm trying to get at.

 

[Rahz]

Totally agree, but are we looking for easier or more accurate

I'm hoping the shape of things can be revealing without needing to be super accurate.

 

[churchhaze]

The best I got so far was 1.6g/W from about 11.5W/sqft of PAR. That was with C99. I'm trying with PPP now, of course like others are saying, veg time is a big variable, and 13/11 means 1 hour more light per day.

 

[The Dawg]

Personally I am fed up with the infinite variables [it seems] of just GPW.....

I Hear Brother!!! Here's What I Know, Show Me A Man That Doesn't Eat His Wife's Snatch And I'll Show You A Man That Will Take His Wife From Him Rocking Ho Rocking Ho The Price Of Meat Has Just Gone Up And Your Old Lady Has Just Gone Down

 

[PurpleBuz]

there are TOO many variables in a survey of GPW to be useful without an extremely large set of survey data.
don't mean to be a downer just being realistic.

the photosynthesis chart you were referring to was done monitoring individual leafs for O2 production with controlled consistent conditions and only the variables in question being varied.

is that GPW in a 4x4 or a 5x5 ?
is that 2 months or 4 months total grow time ?
what strains ?
with or without supplemental CO2?
dwc, ebb & flow, soil ?
harvest for flowers or harvest for oil ?
KIND led, BML leds, or COB leds ?


...... etc.

 

[doz]

there are TOO many variables in a survey of GPW to be useful without an extremely large set of survey data.
don't mean to be a downer just being realistic.

the photosynthesis chart you were referring to was done monitoring individual leafs for O2 production with controlled consistent conditions and only the variables in question being varied.

is that GPW in a 4x4 or a 5x5 ?
is that 2 months or 4 months total grow time ?
what strains ?
with or without supplemental CO2?
dwc, ebb & flow, soil ?
harvest for flowers or harvest for oil ?
KIND led, BML leds, or COB leds ?


...... etc.

Some of your questions are already in the OP..................

 

[Stephenj37826]

Interesting. But I'd guess that you'd get most gpw from low PPFD, like 200-400.



I think that this would be more appropriate

I'm hoping the shape of things can be revealing without needing to be super accurate.

I Hear Brother!!! Here's What I Know, Show Me A Man That Doesn't Eat His Wife's Snatch And I'll Show You A Man That Will Take His Wife From Him Rocking Ho Rocking Ho The Price Of Meat Has Just Gone Up And Your Old Lady Has Just Gone Down

Lmao

 

[PurpleBuz]

Some of your questions are already in the OP..................

wasn't asking for answers to the questions.