DIY Apogee SQ 500 equivalent for £17 / 99% accurate ppfd meter

[man10101]

Hello and thanks for reading!

found this vid a while back
channel is Migro and is def worth checking out
helped me get full control over my light output

basically gives u a way of getting Apogee SQ 500 ($400-$500) equivalent readings by using a UNI-T ut383 lux meter ($20)

if u dont wana watch the vid u simply take the reading from the ut383 and X 0.014

i.e. ut383 reading 38790

38790 X 0.014 = 543.06

ppfd = 543

* if uve got a large grow area (mine is 2.4m X 1m) for a really easy life buy multiple meters
i got 12 spaced them out on a board in 2 rows at 150mm / 6" spacing and take 12 readings at once

saves loads of time!

 

[Death The Cultivator]

Hello and thanks for reading!

found this vid a while back
channel is Migro and is def worth checking out
helped me get full control over my light output

basically gives u a way of getting Apogee SQ 500 ($400-$500) equivalent readings by using a UNI-T ut383 lux meter ($20)

if u dont wana watch the vid u simply take the reading from the ut383 and X 0.014

i.e. ut383 reading 38790

38790 X 0.014 = 543.06

ppfd = 543

* if uve got a large grow area (mine is 2.4m X 1m) for a really easy life buy multiple meters
i got 12 spaced them out on a board in 2 rows at 150mm / 6" spacing and take 12 readings at once

saves loads of time!

It's a conversation factor that isn't entirely accurate because lux meters only measure blue and red spectrums of light whereas Par meters measure the 400-700nm range, extended meters are 300-1000nm. It's like using a wrench as a hammer, it "works" but isn't the right tool for the job. There is a reason precision equipment exist plus there are sub $250 options as well as the pulse pro meters

 

[man10101]

Hi @Death The Cultivator !
Thanks for your reply

Did you watch the video?
If u go to 2:48 u see the comparison chart between the ut383 and 3 other lux meters compared to an Apogee SQ 500 (a scientific grade sensor)

the 3 other lux meters dont really come close to the Apogee so as you say conversions arent usually accurate

however the readings of the ut383 are pretty much identical to the readings of the Apogee SQ 500

U r right and the best tool for the job is the right tool for the job
but even $250 is way out of reach for me
and altho not 100% accurate compared to the Apogee the ut383 is easily close enough for 90% of growers and only costs £17 / $20

and for $20 im a "hit it with a wrench" kind of guy!

 

[Death The Cultivator]

Hi @Death The Cultivator !
Thanks for your reply

Did you watch the video?
If u go to 2:48 u see the comparison chart between the ut383 and 3 other lux meters compared to an Apogee SQ 500 (a scientific grade sensor)

the 3 other lux meters dont really come close to the Apogee so as you say conversions arent usually accurate

however the readings of the ut383 are pretty much identical to the readings of the Apogee SQ 500

U r right and the best tool for the job is the right tool for the job
but even $250 is way out of reach for me
and altho not 100% accurate compared to the Apogee the ut383 is easily close enough for 90% of growers and only costs £17 / $20

and for $20 im a "hit it with a wrench" kind of guy!

I've seen the video before and that is why I said what I said.

If a PAR meter is out of price range then the manufacturer would have been responsible enough to provide maps to ensure proper hanging heights. From that point a grower could calculate DLI for a given time unless that manufacturer lies in their results. Horticulture Lighting Group, ChillLED, Mars, Spider Farmer, Electric Sky, etc. all have maps available online for their lights in given spaces.

Having the right tool aids in being consistent because consistency drives repeatable results in the grow room. I also understand that growers dim their lights rather than adjusting height and IME a PAR meter is preferable because it is accurate.

The majority of growers are technically amateur Controlled Environment Agriculturist doing quite a few scientific things. Consider that $180-500 to be an investment and insurance for future high quality cannabis just like the lights/tents/fertilizers/meters/fans(cheap fans have been known to catch on fire). When something goes wrong then you have the right tools to judge the issues and take the appropriate measures.

 

[Talonxracer]

This "hack" may not be a 100% analog for a quality PAR meter, but it is still highly useful for being able to have a repeatable measurement for "your specific" grow situation like managing plant and light positioning.

A very worthy stand-in for the budget conscious grower to utilize for sure!

 

[Death The Cultivator]

This "hack" may not be a 100% analog for a quality PAR meter, but it is still highly useful for being able to have a repeatable measurement for "your specific" grow situation like managing plant and light positioning.

A very worthy stand-in for the budget conscious grower to utilize for sure!

Use the manufacturer chart, it is a preferable stand in for the budget conscious grower.

 

[man10101]

This "hack" may not be a 100% analog for a quality PAR meter, but it is still highly useful for being able to have a repeatable measurement for "your specific" grow situation like managing plant and light positioning.

A very worthy stand-in for the budget conscious grower to utilize for sure!

theyve really made my life a LOT easier
especially wen it comes to working out different heights/strengths for different stages!

 

[man10101]

Use the manufacturer chart, it is a preferable stand in for the budget conscious grower.

sorry but ive a custom made area of 2.4m X 1m not a standard 4 X 4
ive 2 of the same led panel that im trying to get the right distance apart for both max strength plus most even coverage whilst being offset from centre to accommodate heaters and humdifiers

they dont do coverage maps for everything...

 

[Death The Cultivator]

sorry but ive a custom made area of 2.4m X 1m not a standard 4 X 4
ive 2 of the same led panel that im trying to get the right distance apart for both max strength plus most even coverage whilst being offset from centre to accommodate heaters and humdifiers

they dont do coverage maps for everything...

I've been in the same situation building grow lights for myself and others - renting, buying used, or even returning one after mapping everything out is the best way to achieve accuracy.

I'm not telling you to do that but it's one sided because most growers don't know enough about Lighting to understand why a PAR meter is preferred. When I see that video circulating I say something because some growers invest quite a bit into their setups to rely on a wrench to a hammers job.

In my commercial work a difference of 50umols could induce stress and reduced growth(especially in veg) so without that precision equipment to ensure readings are accurate, undesirable conditions could be introduced into a grow that a lux meter could not account for.

To each their own but my information isn't any less valid than the band-aid that is using a lux meter to do what it was not intended for.

You also mention you have 12 lux meters measuring at $20 a pop you paid for a PAR meter.