Im working with 36” vertically, I went from an all cfl setup to this led to decrease heat and like you mentioned, also increase yield. I can’t get a “better light” because I can’t go any higher with the 65 I already have. And it’s dimmable which brings me back to the meter, I’m worried full power is too much for my plants at max height that my box allows, so I want the meter to figure out where to gauge the dimmer because it’s just a dial, there’s nothing to reference like a 25%, 50% mark etc.
Lux to par graph/conversion
- Thread starter SteakBags
- Start date
cobshopgrow
Well-Known Member
a luxmeter is good to get some values you can compare with each other.
it also shows the spread of the light very well.
best is to get your lux readings in relation with the signs the plant is telling you.
its a bit problematic to calculate par/ppfd numbers out of lux readings.
i have a cheap luxmeter as also a spectrometer and the lux values arent really comparable.
next problem is that the converters avaiable not even give the same values when you convert lux to ppfd.
horticulturelightinggroup.com
when i enter 200 lux for the v2 288 QB with 3000K and 4000K i get 2.91 and 2.88
if i enter the 200 lux here for a 3500K low cri led.
www.waveformlighting.com
i get 3.21, so something dont match.
this plus that the luxmeter is 20-30% of makes it kind of senseless in my eyes to convert.
it also shows the spread of the light very well.
best is to get your lux readings in relation with the signs the plant is telling you.
its a bit problematic to calculate par/ppfd numbers out of lux readings.
i have a cheap luxmeter as also a spectrometer and the lux values arent really comparable.
next problem is that the converters avaiable not even give the same values when you convert lux to ppfd.
Converting Lux to PPFD & Measuring Lux with Smartphone
Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...
horticulturelightinggroup.com
when i enter 200 lux for the v2 288 QB with 3000K and 4000K i get 2.91 and 2.88
if i enter the 200 lux here for a 3500K low cri led.
Convert Lux to PPFD - Online Calculator | Waveform Lighting
Online calculator to convert illuminance (lux) to PPFD (micromoles per second per meter squared).
i get 3.21, so something dont match.
this plus that the luxmeter is 20-30% of makes it kind of senseless in my eyes to convert.
the waveform one seemed off to me based off the graphs I posted, I mean I guess the graphs are accurate because they’re using that expensive par meter but it’s difficult to get exact numbers off of them ..and on that hlg link, idk what light to compare my 65 to so I wasn’t using that eithera luxmeter is good to get some values you can compare with each other.
it also shows the spread of the light very well.
best is to get your lux readings in relation with the signs the plant is telling you.
its a bit problematic to calculate par/ppfd numbers out of lux readings.
i have a cheap luxmeter as also a spectrometer and the lux values arent really comparable.
next problem is that the converters avaiable not even give the same values when you convert lux to ppfd.
Converting Lux to PPFD & Measuring Lux with Smartphone
Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...
when i enter 200 lux for the v2 288 QB with 3000K and 4000K i get 2.91 and 2.88
if i enter the 200 lux here for a 3500K low cri led.
Convert Lux to PPFD - Online Calculator | Waveform Lighting
Online calculator to convert illuminance (lux) to PPFD (micromoles per second per meter squared).
i get 3.21, so something dont match.
this plus that the luxmeter is 20-30% of makes it kind of senseless in my eyes to convert.
If I was to go off the plant, I would say the bigger of the two likes the 65 dimmed down to about 20-30% at 18”, which sounds too weak. I’m not understanding why it’s drooping with more intense light while the smaller of the two can definitely handle like 75%. This is with two 23w 2700k cfls with reflectors on opposite sides of the box. Meter just makes sense for what I’m trying to figure out.
Dontjudgeme
Well-Known Member
Anyone ever seen this site? Found it pretty interesting as long as you have the information from your light to plug in. Very interesting results.
www.cocoforcannabis.com
Grow Light Calculator - Coco For Cannabis
Our grow light calculator provides an accurate way to analyze & compare grow light fixtures. Enter your own grow light data or select preloaded fixtures.
www.cocoforcannabis.com
cobshopgrow
Well-Known Member
the calc is sweet you just need some real par numbers to use it.
and there is also much room for error, like if you clacultate your tent according the given manufactorer data or real measurements.
for my 3x3 it would make a difference form 2.58-2.82 usable ppfd.
its nice that HLG have the PAR map for the 65.
go after the chart like moflow posted, best data you can get and read your plants.
if they drop heavy go lower with the PAR and see later if they can take more, things may clear up soon.
temp, vpd etc. are maybe things to improve too.
and there is also much room for error, like if you clacultate your tent according the given manufactorer data or real measurements.
for my 3x3 it would make a difference form 2.58-2.82 usable ppfd.
its nice that HLG have the PAR map for the 65.
go after the chart like moflow posted, best data you can get and read your plants.
if they drop heavy go lower with the PAR and see later if they can take more, things may clear up soon.
temp, vpd etc. are maybe things to improve too.
ilovereggae
Well-Known Member
I have used the HLG65 (without dimmer) in a 2x2x3 tent and it wasn't great. The non dimmed light is too strong for clones/seedlings even at full height. If you can dim it, you should be fine. But then turning it up to full blast and having it right at the top of the tent didn't work (at least with driver mounted to the back of it) bc it generated too much heat. I had to drop it a few inches to let a fan circulate air between the fixture and top of tent. This only left me with a couple of weeks it was useful during a grow. I just bought the dimmer HLG has on their Amazon store and as soon as my current harvest is done drying I am going to give it another go to see if I can use it for early veg.
Unless you are flowering clones and training from the very beginning, and mount the driver outside the tent to deal with excess heat, it's going to be tough to pull off the entire grow inside that thing. Like others have said, the meter doesn't really mean much at this point. Numbers that other people use for reference won't apply to you since you are dealing with a 'micro' environment. Also different strains even different phenos of same strain respond differently to light, so for now, don't worry about being that specific.
I would save the $ on the meter and just feel it out at first. If the plants look like the want more light, turn it up. If they are looking like they are getting too much, turn it down. No matter how you approach this, you are going to have to do a few rounds until you are comfortable with the plants, and learn what they want.
Unless you are flowering clones and training from the very beginning, and mount the driver outside the tent to deal with excess heat, it's going to be tough to pull off the entire grow inside that thing. Like others have said, the meter doesn't really mean much at this point. Numbers that other people use for reference won't apply to you since you are dealing with a 'micro' environment. Also different strains even different phenos of same strain respond differently to light, so for now, don't worry about being that specific.
I would save the $ on the meter and just feel it out at first. If the plants look like the want more light, turn it up. If they are looking like they are getting too much, turn it down. No matter how you approach this, you are going to have to do a few rounds until you are comfortable with the plants, and learn what they want.
JoeBlow5823
Well-Known Member
Yeah I wouldnt see a LUX meter being very useful in a small tent. I just like having mine for my 5x5 because im running a single 1000w light and the center is definitely hot. Helps me train the plants short in the middle and tall on the outsides so they all get similar light.
nc208
Well-Known Member
If any of y'all are interested the seneye reef monitor designed for aquariums is the cheapest option you can go. It's been tested against the apogee and licor and have surprisingly accurate results. Just over 200 bucks. It doesnt require the subscription service to use the par meter.
www.bulkreefsupply.com
Seneye Reef Monitor
Seneye Reef Pack is an all in one monitor for Temperature, Ammonia, pH, Water level, and Lighting. With a PC you can connect your Seneye monitor directly to any PC or Seneye Web Server to monitor your aquarium. With the Seneye Web Server you can monitor your aquarium from anywhere you can get...
www.bulkreefsupply.com
end_of_the_tunnel
Well-Known Member
In the old HPS days, it was pretty easy for everyone to be on same page with lighting levels. But now, dimmers and a wide range of different configurations/quantity of even the same type of diode can leave anyone guessing. A cheap lux meter is better than nothing. Even if it does not provide accurate true figures, it is still useful as a yardstick to help a user adjust lighting levels.
I have more faith in the HLG conversion page than the Waveform lighting one.
horticulturelightinggroup.com
I have more faith in the HLG conversion page than the Waveform lighting one.
Converting Lux to PPFD & Measuring Lux with Smartphone
Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...
horticulturelightinggroup.com
cobshopgrow
Well-Known Member
problem is when you take the converted values, or even the lux values themself, and go after the usual recomendations.
salmonetin
Well-Known Member
...A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you are getting with the Lumens/PPF ratio to get the PPFD value....In the old HPS days, it was pretty easy for everyone to be on same page with lighting levels. But now, dimmers and a wide range of different configurations/quantity of even the same type of diode can leave anyone guessing. A cheap lux meter is better than nothing. Even if it does not provide accurate true figures, it is still useful as a yardstick to help a user adjust lighting levels.
I have more faith in the HLG conversion page than the Waveform lighting one.
Converting Lux to PPFD & Measuring Lux with Smartphone
Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...
...Use for reference only....
Every Board spectrum may be slightly different.
Board temperature and Phosphorus aging also change spectrum causing Lumens/PPF to shift over time.
...Use a calibrated Lux meter for better accuracy...
...estoy de acuerdo pero...
...yo estoy muy curioso por ver datos obtenidos por lux meters calibrados contra leds de bines confiables aparte de estar calibrados contra la lampara de mercurio reglamentaria...
...pero no veo a nadie ...calibrando contra leds de bines conocidos y confiables... y hablo de led blancos ...si hay led de colores de por medio... hablamos de un calibrado contra esa lampara ...llamemosla lampara patron....
...y tampoco veo que actualmente se haga.... es solo mi pov sobre el tema...
...and thanks for the link EOT ... otra actualizacion a bordo...
...viejo tema... e interesante para los que no nos podemos permitir hardwares caros y precisos... pero estoy desactualizado y lo mismo hay otras maneras o hardwares mas baratos que nos puedan ayudar a los que vamos cortos de presupuesto... con tiempo sabre mas cosillas... voy sin prisa y con pausas... con 59 vueltas al sol no pretendo correr... se lo dejo a los jovenes...
Saludos
end_of_the_tunnel
Well-Known Member
Even if a cheapo lux meter is off by an amount, in accuracy. The user can still use it as a tool to aid. For example to repeat a setup that has provided results in the past.
If a user has access to PPFD measurement, the figures quoted as guidelines in literature, are simply guidelines.
What you say is very true though, maybe the wisest thing is for users to refrain from converting. If enough people post either lux or PPFD figures, we will start to grow a picture of trends in growth and plant response. Its just frustrating that not everyone can be on same page with measurement tools.
end_of_the_tunnel
Well-Known Member
Yes. This is something cobshopgrow has been trying to emphasise and point out. Your term, "...Use for reference only....". Very good....A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you are getting with the Lumens/PPF ratio to get the PPFD value....
...Use for reference only....
Every Board spectrum may be slightly different.
Board temperature and Phosphorus aging also change spectrum causing Lumens/PPF to shift over time.
...Use a calibrated Lux meter for better accuracy...
...estoy de acuerdo pero...
...yo estoy muy curioso por ver datos obtenidos por lux meters calibrados contra leds de bines confiables aparte de estar calibrados contra la lampara de mercurio reglamentaria...
...pero no veo a nadie ...calibrando contra leds de bines conocidos y confiables... y hablo de led blancos ...si hay led de colores de por medio... hablamos de un calibrado contra esa lampara ...llamemosla lampara patron....
...y tampoco veo que actualmente se haga.... es solo mi pov sobre el tema...
...and thanks for the link EOT ... otra actualizacion a bordo...
...viejo tema... e interesante para los que no nos podemos permitir hardwares caros y precisos... pero estoy desactualizado y lo mismo hay otras maneras o hardwares mas baratos que nos puedan ayudar a los que vamos cortos de presupuesto... con tiempo sabre mas cosillas... voy sin prisa y con pausas... con 59 vueltas al sol no pretendo correr... se lo dejo a los jovenes...
Saludos
cobshopgrow
Well-Known Member
absolute, a cheap lux meter is good to compare results to each other and it tells you how well the light spread.
if 2 people have the same meter and use the same led spectrum, its something.
just, i know another guy with a spectrometer and a cheap luxmeter.
the readings are way of comapring the units and i doubt our spectrometers are of that much.
to give a example, 3000k 80cri, luxmeter 10k, spectrometer 15K.
my cheap luxmeter do have a ISO certified sticker , its just not worth much.
i dont know how much you need to spend for a real calibrated Luxmeter which gives real values, but i guess its in the ballpark of a PAR meter.
the cheap looking calibrated one on the picture is for sure more then a apogee par meter.
i would love to see someone comparing the (no joke) Korona app, iOS, with a real par meter.
i have no iphone, so i cant test myself.
if 2 people have the same meter and use the same led spectrum, its something.
just, i know another guy with a spectrometer and a cheap luxmeter.
the readings are way of comapring the units and i doubt our spectrometers are of that much.
to give a example, 3000k 80cri, luxmeter 10k, spectrometer 15K.
my cheap luxmeter do have a ISO certified sticker , its just not worth much.
i dont know how much you need to spend for a real calibrated Luxmeter which gives real values, but i guess its in the ballpark of a PAR meter.
the cheap looking calibrated one on the picture is for sure more then a apogee par meter.
i would love to see someone comparing the (no joke) Korona app, iOS, with a real par meter.
i have no iphone, so i cant test myself.
salmonetin
Well-Known Member
post movido sorry
SAludos
SAludos
Last edited:
This may help. You can select different spectrums:
Convert Lumens to PPF - Online Calculator | Waveform Lighting
Online calculator to convert luminous flux (lumens) to PPF (micromoles per second).
end_of_the_tunnel
Well-Known Member
Maybe also look at this page from HLG?
Converting Lux to PPFD & Measuring Lux with Smartphone
Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...
horticulturelightinggroup.com
Or maybe i shoulda read the thread? My bad, you made some great points. I am waiting on my cheapo meter to arrive...Maybe also look at this page from HLG?
Converting Lux to PPFD & Measuring Lux with Smartphone
Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...