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SpiderFarmer SE3000 PPFD Chart, Accurate?

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SpiderFarmer SE3000 PPFD Chart, Accurate?

Dothraki 50 Replies 17,056 Views
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Dothraki

Dothraki

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#1
Hey all,

I am getting ready to start my first grow, 3x3 tent, LED light (SF SE3000) with dimmer switch.

Learning about PPFD, if the chart provided by the manufacturer is accurate (with obvious error margins between productions), can I use this to calculate PPFD at each distance or is there a curve that’s impossible to know?

I’ve heard these charts are very inaccurate. What’s the story with them?
Spiderfarmer se3000 ppfd chart accurate
 
#2
I’m trying to get an idea of what height at each growing phase from seed I would start with. Keeping in mind this was tested in a grow tent so readings are higher than a 3rd party test.
 
#3
Dothraki said:
Hey all,

I am getting ready to start my first grow, 3x3 tent, LED light (SF SE3000) with dimmer switch.

Learning about PPFD, if the chart provided by the manufacturer is accurate (with obvious error margins between productions), can I use this to calculate PPFD at each distance or is there a curve that’s impossible to know?

I’ve heard these charts are very inaccurate. What’s the story with them?View attachment 1182372
Click to expand...
Looks pretty suspect to me. I would think 2" would make more difference.
 
#4
growsince79 said:
Looks pretty suspect to me. I would think 2" would make more difference.
Click to expand...
It’s also kinda funny they only showed a specific 2“ area for the reading. I’m assuming that drop off is horrible after 10” and that’s why they didn’t give us 12” or 18” or 24”.
 
#5
Dothraki said:
It’s also kinda funny they only showed a specific 2“ area for the reading. I’m assuming that drop off is horrible after 10” and that’s why they didn’t give us 12” or 18” or 24”.
Click to expand...
They also say 6-10" in flower. With the PAR they claim would kill anything I try to grow. 700ppfd is more than enough for my soil grows.
 
#6
growsince79 said:
They also say 6-10" in flower. With the PAR they claim would kill anything I try to grow. 700ppfd is more than enough for my soil grows.
Click to expand...
Damn...lol. Yeah maybe I need to find someone that’s used this light and get some basic ideas for distance because obviously the company is either A. Smearing the facts, or B. Just flat out lying
 
#7
Just get a free light meter app for your phone.
 
#10
Based off this chart does anyone have an idea of percentage and distance you would start with for once the seed pops, seedling phase, veg, flower? Like 30“/25% first two weeks, etc,
 
#12
Dothraki said:
Based off this chart does anyone have an idea of percentage and distance you would start with for once the seed pops, seedling phase, veg, flower? Like 30“/25% first two weeks, etc,
Click to expand...
I just got this light set up yesterday. I have it 19" from a Bubble Bomb that was about 6 weeks old before I flipped her 5 days ago. I get a lux reading of around 30,000. I was keeping her around 24" from a SF1000 I started her under giving me a lux 8,000 .@60% ..I moved her up to 20,000 lux before I flipped her
 

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#13
What if I did 10” @ 25% for seedling, 10” @ 60% Veg, and 100% for flowering? Based on the chart I posted?
 
#15
growsince79 said:
1200ppfd would kill anything I try to grow.
Click to expand...
I think they exaggerate the numbers...but better to be safe. I would try raising it to 12” or so... but I‘m not sure if the method of estimating I’m using is right.
 
#16
growsince79 said:
1200ppfd would kill anything I try to grow.
Click to expand...
One thing I’m not understanding is distance vs intensity. So if a light was reading, let’s say 500 PAR @ 20”, and you bring it closer to the plant at 10” but dimming it to get the same 500 PAR...would it still be the same result on the plant? And...is there a way to calculate the PAR by using a percentage drop off per inch? Or does that have to be done manually with readings at each inch?
 
#17
Dothraki said:
One thing I’m not understanding is distance vs intensity. So if a light was reading, let’s say 500 PAR @ 20”, and you bring it closer to the plant at 10” but dimming it to get the same 500 PAR...would it still be the same result on the plant? And...is there a way to calculate the PAR by using a percentage drop off per inch? Or does that have to be done manually with readings at each inch?
Click to expand...
My lights don't have dimmers so idk.
 
#18
Dothraki said:
Hey all,

I am getting ready to start my first grow, 3x3 tent, LED light (SF SE3000) with dimmer switch.

Learning about PPFD, if the chart provided by the manufacturer is accurate (with obvious error margins between productions), can I use this to calculate PPFD at each distance or is there a curve that’s impossible to know?

I’ve heard these charts are very inaccurate. What’s the story with them?View attachment 1182372
Click to expand...
I have a sf4000, I have a 4x4. This light @ 100% output, has the best growth rate @ 24 inches. This height has optimum photon spread across the space. The edge ppfd is approx. 507 and the center is 850.

 
#19
Dothraki said:
One thing I’m not understanding is distance vs intensity. So if a light was reading, let’s say 500 PAR @ 20”, and you bring it closer to the plant at 10” but dimming it to get the same 500 PAR...would it still be the same result on the plant? And...is there a way to calculate the PAR by using a percentage drop off per inch? Or does that have to be done manually with readings at each inch?
Click to expand...

Hello. I've been reading your thread and may I just interject that the formula for calculating what your PAR/PPFD at any given distance change is what is known as the Inverse Square Law applicable to all forms of light, visible and invisible. Hope this helps. Intensity 1 over Intensity 2 = Distance 2 (squared) over Distance 1 (squared) Just set up the equation as I have it here, square your Distances 1 & 2 and then cross-multiply. Results will demonstrate mathematically that when you reduce the distance by 1/2 you increase the light intensity value X 4 Conversely if you double the new distance from the light source you will end up with 1/4 the light intensity. You can review the Inverse Square Law online and get a working formula where you can plug in your own values.

​

 
#20
growsince79 said:
My lights don't have dimmers so idk.
Click to expand...
tucume66 said:
Hello. I've been reading your thread and may I just interject that the formula for calculating what your PAR/PPFD at any given distance change is what is known as the Inverse Square Law applicable to all forms of light, visible and invisible. Hope this helps. Intensity 1 over Intensity 2 = Distance 2 (squared) over Distance 1 (squared) Just set up the equation as I have it here, square your Distances 1 & 2 and then cross-multiply. Results will demonstrate mathematically that when you reduce the distance by 1/2 you increase the light intensity value X 4 Conversely if you double the new distance from the light source you will end up with 1/4 the light intensity. You can review the Inverse Square Law online and get a working formula where you can plug in your own values.

​

Click to expand...
Dr. Bruce Bugbee who heads the Agricultural program at Utah University and is President of Apogee Instruments has many videos on Youtube that you may want to watch - here is one that relates to PAR/PPFD, etc.
 
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