Ppfd :-)

Kingrow1

Kingrow1

Well-Known Member
I was looking for ppfd data on t5 flourescents, preferably 4x24w models at distances in tents. Ive found some hps data -

https://www.sanlight.com/en/substitution-of-light-sources/

- seems genuine?

Would also love to see cmh data as not looked for that yet.

Indoor ppfd seems less than outdoors but im going to say thats a factor of daily light intergral (dli). Plants outdoors adapt to a varied ppfd but indoors id guess become more sensitive to change as less adaption and such systems of regulation are used. Max a seedling with light and then put it back to normal intensity and it will be better at dealing with futher high intensities - i guess thats whats at play there.

Quantum meters - exspensive so rely on data to set lights here, bummer but just like ferts once you know the dose in ml theres no need to.check ppm. Lost faith in light charts - seen a lot of ppfd data for germ to flower say 100umols to 800umols approx and guessing a little.

Anyone setting lights to ppfd/umols and finding its worked and any advice for levels? Guess leds have the jump on me here, i envisage them using raw numbers to dictate height per tent area and plant stage.

Anything is appreciated :-)
 
Kingrow1

Kingrow1

Well-Known Member
Yer out of my price range, use to be plentifull data but every search just nets a list of led stuff thesedays.

Oh well guess im going to have to do more searching :-)


.RootDown said:
An Apogee quantum meter is only about five hundred bucks. Not exactly cost prohibitive if you want the data.
Click to expand...
 
Moflow

Moflow

Well-Known Member
Checkout around 2mins 20 secs for T5 fixture

Check out 2mins 50 secs in par test
Hope that helps in your quest.

These look nice..... led tho....
activegrowled.com

T5 HO Plug & Play 4FT LED Grow Lamp – Sun White Spectrum

Our high efficacy T5 grow lamps guarantee tighter internodal spacing & fuller, heartier plants. Easy plug & play installation. Low heat output is safe for plants & growers.
activegrowled.com activegrowled.com
 
Kingrow1

Kingrow1

Well-Known Member
Why didnt leds match the wattage of t5's - be intrested then but hard to swap out 24w daylight spectrums for 14w of led. Id have gone for quality and power not efficiency there imo :-)


Moflow said:
Checkout around 2mins 20 secs for T5 fixture

Check out 2mins 50 secs in par test
Hope that helps in your quest.

These look nice..... led tho....
activegrowled.com

T5 HO Plug & Play 4FT LED Grow Lamp – Sun White Spectrum

Our high efficacy T5 grow lamps guarantee tighter internodal spacing & fuller, heartier plants. Easy plug & play installation. Low heat output is safe for plants & growers.
activegrowled.com activegrowled.com
Click to expand...
 
B

Bengfan

Active Member
Kingrow1 said:
Yer out of my price range, use to be plentifull data but every search just nets a list of led stuff thesedays.

Oh well guess im going to have to do more searching :-)
Click to expand...
In my opinion, "light" meters are useless for plants. Each plant is going to react to light levels and intensities differently. Therefore, reading the plant is far more useful than what some meter could tell you. While one plant does great at x number of umols, the one right beside it may burn up! The meter could get you to a starting point I guess, but for the hundreds you spend for that meter is it really worth it?
 
L

LinguaPeel

Well-Known Member
Glad to see at least one clown on the internet care about real science information. I put my first led 2" over my plants because internet growers are stupid hippies and didn't tell me they aren't cfls.
 
Kingrow1

Kingrow1

Well-Known Member
rkymtnman said:
And no more wasting money on buying bulbs. He probably could have saved enough to buy a decent meter and do his own testing.
Click to expand...
I did a thread a while back and the calculations for ppfd from lumens/lux but just found it not quite so accurate.

Id love a meter - could post data on ppfd for plant stage, dont see or here much talk there even though ppfd is big with led and such :-)
 
Kingrow1

Kingrow1

Well-Known Member
I cant spend hundreds on a meter byt havecas well considered this. If all my plants are of the same health stage and size it should be easier to set and keep all happy.

Theres big hotspots on all lights which.is a higher ppfd to the edges so another gradient that will alter indiividual plant light - historically we could rotate plants daily.

Its far from perfect but id prefer a few more set points as mainly just read plants and set height then raise and lower different stages.

:-)



Bengfan said:
In my opinion, "light" meters are useless for plants. Each plant is going to react to light levels and intensities differently. Therefore, reading the plant is far more useful than what some meter could tell you. While one plant does great at x number of umols, the one right beside it may burn up! The meter could get you to a starting point I guess, but for the hundreds you spend for that meter is it really worth it?
Click to expand...
 
Kingrow1

Kingrow1

Well-Known Member
I think its the only variable i have left that isnt through scientific approach - it seems to dictate leaf temps and stress there.

:-)

LinguaPeel said:
Glad to see at least one clown on the internet care about real science information. I put my first led 2" over my plants because internet growers are stupid hippies and didn't tell me they aren't cfls.
Click to expand...
 
Kingrow1

Kingrow1

Well-Known Member
bk78 said:
If the internet told you to jump off a bridge would you?
Click to expand...
Fuck yer, obviously id just typed in "Best bridge umping spots" and joined the up and coming tombstoners of the world......

Why you ask? Wanna join me and my mates and let of some of that stress that you got built up..... :-)
 
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