optimal watt / square foot or m2

[Shugglet]

From 100 PPFD you get 20 % of max. 350 -> 50 %. After that you need a lot more PPFD to increase photosynthesis. So the optimum I asked is somewhere 100-350 PPFD.

At 100ppfd you get ~18%.

At 300ppfd you get ~47%. So a tripling of ppfd nets you a ~29% increase in photo.

At 600pfd you get ~77%. Now it only takes a doubling of ppfd to net you an additional ~30% photo. (not really diminishing in the returns department, is it?)

Given this info Im not sure why you feel 350 is optimal...

Also, with ppfd remaining constant, more space will ALWAYS yield more.

 

[Bolof]

View attachment 3825193

Please leave me alone. You are an idiot. I have no interest in discussing with you.

 

[Shugglet]

Thus, you dont know what optimal means, as a technical term.

No offense, but how is cutting something off long before diminishing returns kicks in "optimal"?

And by all means, feel free to get as "technical" as you want. I feel I got plenty technical using the chart to show how I think you are wrong here even by your own logic...

 

[Shugglet]

This silence is just golden, I can tell you have a VERY hard time admitting when youre wrong.

 

[Bolof]

This silence is just golden, I can tell you have a VERY hard time admitting when youre wrong.

I am not wrong. But you are. You have rudimentary knowledge of math.

 

[Bolof]

No offense, but how is cutting something off long before diminishing returns kicks in "optimal"?

And by all means, feel free to get as "technical" as you want. I feel I got plenty technical using the chart to show how I think you are wrong here even by your own logic...

Return is actually dimishing all the time. Even going 100 to 200 return dimish. Look at how many % each 100 add. Do the very simple math.

 

[Bolof]

At 100ppfd you get ~18%.

At 300ppfd you get ~47%. So a tripling of ppfd nets you a ~29% increase in photo.

At 600pfd you get ~77%. Now it only takes a doubling of ppfd to net you an additional ~30% photo. (not really diminishing in the returns department, is it?)

Given this info Im not sure why you feel 350 is optimal...

Also, with ppfd remaining constant, more space will ALWAYS yield more.

The first 300 gives you 47 %. The next 300 add 30 %. A lot less then the first 300.

 

[Trippyness]

You want 900 PPFD regardless of light source.
What light source are you working with?
DE?
COB?
Blurple?
HPS?
CMH?

 

[Bolof]

You want 900 PPFD regardless of light source.
What light source are you working with?
DE?
COB?
Blurple?
HPS?
CMH?

I will probably start with HPS. Later on COB.

 

[Bolof]

You want 900 PPFD regardless of light source

Why? Above 600 is not giving much more?

 

[Trippyness]

I will probably start with HPS. Later on COB.

If your starting a CMH is better than a HPS but if your budget is limited HPS is still good for the money ( if your low on funds)
What space you working with?

 

[Trippyness]

Why? Above 600 is not giving much more?

This
https://www.rollitup.org/t/photosynthesis-per-100-ppfd.880834/

You understand the difference between 600PAR vs 600PPFD right?

 

[Bolof]

If your starting a CMH is better than a HPS but if your budget is limited HPS is still good for the money ( if your low on funds)
What space you working with?

I will rebuild the house, so it is just a plan for now. But after it is rebuilt I cannot expand the space. 20 - 40 m2 basement is possible.

 

[Shugglet]

The first 300 gives you 47 %. The next 300 add 30 %. A lot less then the first 300.

For every unit of ppfd you add between 100 and 300 ppfd you get an additional .1% photo rate.

For ever unit of ppfd you add between 300 and 600 you get an additional .1% photo rate.


By your logic, you should stop even earlier then, because for every ppfd you add between 0 and 100 you gain .18% Roughly twice the return on ppfd than even 100-300.

Even if you use a zero baseline for 300ppfd you gain .157% per unit increase vs a .128% increase for ever unit at 600ppfd.

After 600ppfd the chart flattens out so diminishing returns start significantly cutting into efficiency.

 

[Shugglet]

I will rebuild the house, so it is just a plan for now. But after it is rebuilt I cannot expand the space. 20 - 40 m2 basement is possible.

Sounds like you need to plan out a budget before you do anything...

Remember that growing is like cat skinning, theres practically an unlimited number of ways it can be done correctly.

 

[Olive Drab Green]

Why? Above 600 is not giving much more?

..You clearly don't know how this works, brother. 850PPFD is about what a plant needs for 85-90% productivity. 1200 max. After 1200PPFD, photoinhibition may occur. 600PPFD is maybe 60% of the PPFD optimal for a crop to grow to its potential.

 

[Olive Drab Green]

"The graph below describes the relationship between light intensity and plant growth. As you can see the lower intensities produce less growth but are also more efficient. A PPFD of 400 achieves over 50% growth potential while a PPFD of 800 improves the growth to about 85% but not doubling it. As the light intensity approaches 1500 the amount of additional growth slows and light intensities above 1500 will begin to harm a plant. A common balance between performance and efficiency is in the 600-900 PPFD range.
"

 

[Bolof]

..You clearly don't know how this works, brother. 850PPFD is about what a plant needs for 85-90% productivity. 1200 max. After 1200PPFD, photoinhibition may occur. 600PPFD is maybe 60% of the PPFD optimal for a crop to grow to its potential.

Read your next post. "a common balance" = what you suggest. But that is not what I asked for. Your 2nd post say exactly what I have been saying lately.

 

[Olive Drab Green]

Read your next post. "a common balance" = what you suggest. But that is not what I asked for. Your 2nd post say exactly what I have been saying lately.

You have been saying "600PPFD is acceptable." I think you should aim higher. Why waste your time on 60% of a plant?

 

[Bolof]

Read your next post. "a common balance" = what you suggest. But that is not what I asked for. Your 2nd post say exactly what I have been saying lately.

Lower intensities are more efficient = the answer to my question. BUT that require lots of space. It is not a "balanced" approach.