Cheap LUX meter to calculate PAR and DLI

[BadGrandpa007]

Hi, i had the idea to buy a cheap LUX meter to calculate the aproximate DLI and PAR. I see people are doing that. Some guys alrady calibrated some meters from The apogee PRO devices. ChatGPT says he can calculate the data for me, it just needs the LEDs SPD data and i have it. My LED is Mars Hydro SP250W, perfect for 2x4space. The PAR meters are sooo expensive, i just cant afford them, so i thought this would be a solution, better that nothing at all.. Im wondering what would be the calculation error from LUX to PAR even if the Ai calculates it from the SPD data.. i thought if the error would be some 5-10% it not so important i could just adjust the height with lets say 10% reserve.. What do you think about this?

 

[ProPheT 216]

Don't the companies provide maps? All I need is a tape, even then I tend to let them get to high. Smh

 

[BadGrandpa007]

Don't the companies provide maps? All I need is a tape, even then I tend to let them get to high. Smh

it has a map, but it doesnt tell any story, the map , the radings are from one height and if i want to adjust or dim the LED, the measurements will differ, so i dont think i can use the manufacturers data in all cases..

 

[ProPheT 216]

Leave the light on max, set where you want it to be height wise. Let the plants go after it and train them at the distance you want. No need to complicate things

 

[ProPheT 216]

Also not saying it's a waste to not have 1, but a cheap 1 is likely a waste, and a new grower.dosent need 1 for success. To me that's more to dial in your last 5% efficiency before doing something like a sealed room with co2

 

[BadGrandpa007]

Also not saying it's a waste to not have 1, but a cheap 1 is likely a waste, and a new grower.dosent need 1 for success. To me that's more to dial in your last 5% efficiency before doing something like a sealed room with co2

yes , there is a plenty of co2 because the room is small, all rooms actually are small and im living in there. When i ventilate the rooms for a long time next day co2 ppm on the ground in the growtent is already up to 1200-1400ppm, so with these co2 levels the plant can eat more heat and light.. i just dont want to burn them because i grow autoflowers and if i fcuk up the first weeks or the veg cycle so the end result wont be as good as it could be, the tent is 2x4 so i cant grow a lot of plants, thats why im trying to get the best out of the small room.. maybe i just want to complicate things

 

[compassionateExotic]

If u have a iPhone, the app works great good enough to def know ur general % of obvious what Height and zone is giving proper ppfd/strengeth .

it requires a piece of paper over the camera for it to work and they try to charge for led spectrum , but if u follow the led sellers height recommendations and than use that app/cheap lux meter u can def see what helps and also ur best medium of dim % and height for you.

Photone - Grow Light Meter

growlightmeter.com

heard it sucks for andoid since there’s so many models, but I know it works for iPhone fosure

 

[ProPheT 216]

yes , there is a plenty of co2 because the room is small, all rooms actually are small and im living in there. When i ventilate the rooms for a long time next day co2 ppm on the ground in the growtent is already up to 1200-1400ppm, so with these co2 levels the plant can eat more heat and light.. i just dont want to burn them because i grow autoflowers and if i fcuk up the first weeks or the veg cycle so the end result wont be as good as it could be, the tent is 2x4 so i cant grow a lot of plants, thats why im trying to get the best out of the small room.. maybe i just want to complicate things

 

[BadGrandpa007]

If u have a iPhone, the app works great good enough to def know ur general % of obvious what Height and zone is giving proper ppfd/strengeth .

it requires a piece of paper over the camera for it to work and they try to charge for led spectrum , but if u follow the led sellers height recommendations and than use that app/cheap lux meter u can def see what helps and also ur best medium of dim % and height for you.

Photone - Grow Light Meter

growlightmeter.com

heard it sucks for andoid since there’s so many models, but I know it works for iPhone fosure

yeah i tried it on Android phone, it is not useful at all.. but for iphones it really kinda works, i watched many y-tube videos. lucky iphone users..

 

[Kola_Kreator]

yes , there is a plenty of co2 because the room is small, all rooms actually are small and im living in there. When i ventilate the rooms for a long time next day co2 ppm on the ground in the growtent is already up to 1200-1400ppm, so with these co2 levels the plant can eat more heat and light.. i just dont want to burn them because i grow autoflowers and if i fcuk up the first weeks or the veg cycle so the end result wont be as good as it could be, the tent is 2x4 so i cant grow a lot of plants, thats why im trying to get the best out of the small room.. maybe i just want to complicate things

12-1400 is extremely high number for an ambient C02 level. The average indoor living space might get up to 6 or 700 but it's unlikely to be 1400.

 

[Delps8]

Hi, i had the idea to buy a cheap LUX meter to calculate the aproximate DLI and PAR. I see people are doing that. Some guys alrady calibrated some meters from The apogee PRO devices. ChatGPT says he can calculate the data for me, it just needs the LEDs SPD data and i have it. My LED is Mars Hydro SP250W, perfect for 2x4space. The PAR meters are sooo expensive, i just cant afford them, so i thought this would be a solution, better that nothing at all.. Im wondering what would be the calculation error from LUX to PAR even if the Ai calculates it from the SPD data.. i thought if the error would be some 5-10% it not so important i could just adjust the height with lets say 10% reserve.. What do you think about this?

Attached is a document I wrote to help with the conversion. To convert your Mars SP 250, I'd go with the conversion factor of 0.015.

I tried using Photone back when it was named "Korona" and then a year or so later. In terms of what I'd recommend to determine PPFD, PAR meter, lux meter, Photone only if you can calibrate it against a known good source; manufacturer's recommendations.

After Photone/Korona could not read my blurple (2021), I bought an Apogee and, for a year or so, wasn't keen on using a light meter + the conversion factor. After looking into it a bit, I came to understand why it's so useful - it's a good solution.

A big thing to understand is that an Apogee is calibrated to 5%±. The Uni-T lux meter is manufactured to 5%±. Add in the inaccuracy of picking the wrong conversion and you could be another 20, 30, µmol off.

So?

It really doesn't matter that much because the goal is just to get you into the ballpark and then, if you want to, you can increase the PPFD by watching the plant.

 

[Delps8]

yeah i tried it on Android phone, it is not useful at all.. but for iphones it really kinda works, i watched many y-tube videos. lucky iphone users..

I traded email with the programmer (I've been a software engineer for > 30 years) and that topic came up. He said that Android had an issue of factory calibration not being consistent.

I think it's great to read that growers are interested in lighting there grows well. I'm a high light grower because more light -> better crop.

My take - spend $21 on a Uni-T lux meter and use the conversion factor. It works well.

 

[curious2garden]

It really doesn't matter that much because the goal is just to get you into the ballpark

Exactly we do not require accuracy as much as we require stability, ie that our device measures consistently and that it is consistent in it's error over the domain it's testing.

 

[BadGrandpa007]

I traded email with the programmer (I've been a software engineer for > 30 years) and that topic came up. He said that Android had an issue of factory calibration not being consistent.

I think it's great to read that growers are interested in lighting there grows well. I'm a high light grower because more light -> better crop.

My take - spend $21 on a Uni-T lux meter and use the conversion factor. It works well.

Thanks a lot! i had this (Uni -T UT383 or the Bluetooth version) device in mind after stumbling up on this y-video.. but then in his comments later he mentioned that the correct conversion rate for this device is 0.017 in case if i have also RED IR leds..any way so i will use this conversion rate and will give the SPD data to Ai so it can do what is doe best and i will compare to your PDF..

SP250 SPD is Blue(400 - 500nm): 15.4872% > Green(500 - 600nm): 43.8039% > Red(600 - 700nm): 40.7089% > Total :100% UVB(287-320nm): 0.00759645% > UVA(320-400nm): 0.140558% > Violet_Blue(400-475nm): 13.1032% > Cyan_Green(475-550nm): 17.2152% > Green_Yellow_Red(550-700nm): 65.0914% > FarRed_NearIR(700-850nm): 4.44204%

What light do you have? do you know what the model of the diodes are? Samsung or what?

Yeah , Photon on Adnroid is garbage, even the S20.. phone to phone the reading differ so much.. On latest iPhones its a different story..

 

[BadGrandpa007]

12-1400 is extremely high number for an ambient C02 level. The average indoor living space might get up to 6 or 700 but it's unlikely to be 1400.

it is, i have a pretty expensive co2 measurer, i asked a friend to give it to me, tested it in my house, the ventilation is bad there..

 

[Hollatchaboy]

~1500 ppm of co2 will start causing headaches, dizziness, and sleepiness. I would imagine at 1200-1400 constant, you would feel, at least some; of those effects. Id check your co2 monitor for accuracy.

 

[BadGrandpa007]

~1500 ppm of co2 will start causing headaches, dizziness, and sleepiness. I would imagine at 1200-1400 constant, you would feel, at least some; of those effects. Id check your co2 monitor for accuracy.

the device cost 300usd - its a reliable device, one of the best on the market (Aranet4), i trust it! And yes, you cant imagine how bad the ventilation in my home is, and yes sometimes i have headaches.. so i took this device to test how often and how long i must ventilate my home/rooms not to live in conditions like that.. but for the grow room - i just close the door and leave the plants breathing the co2.. i dont think co2 can be toxic to plants , they need it as we need oxygen and if the light (DLI and PAR) and temps are in line with co2 levels you can get the full potential of the photosyntesis.. if co2 is 400ppm you only get 40% of the canabis plants potential..

 

[curious2garden]

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.

 

[Hollatchaboy]

the device cost 300usd - its a reliable device, one of the best on the market (Aranet4), i trust it! And yes, you cant imagine how bad the ventilation in my home is, and yes sometimes i have headaches.. so i took this device to test how often and how long i must ventilate my home/rooms not to live in conditions like that.. but for the grow room - i just close the door and leave the plants breathing the co2.. i dont think co2 can be toxic to plants , they need it as we need oxygen and if the light (DLI and PAR) and temps are in line with co2 levels you can get the full potential of the photosyntesis.. if co2 is 400ppm you only get 40% of the canabis plants potential..View attachment 5378746

Not saying it's not a reliable device. I'm saying check calibration. I've never heard of co2 levels, that elevated, in someone's home. If your air ventilation is that poor, I would think they could elevate higher, with every breath, and that could be dangerous.

 

[BadGrandpa007]

Not saying it's not a reliable device. I'm saying check calibration. I've never heard of co2 levels, that elevated, in someone's home. If your air ventilation is that poor, I would think they could elevate higher, with every breath, and that could be dangerous.

yes overnight in that room im sleeping it gets even to 2K +.. you cant imagine how small the rooms are when i have visitors it gets to 2K in 3hours when we are sitting in that room, and you can feel the bad air quality, its so dense, i usually open windows when i have visitors, its a mess, but its a old house, trust me, i have ventilation problems - no, better i would say - i dnt have ventialation in that part of house at all..