We all spend a lot of time and effort trying to monitor environmental conditions with our grows.
When I pick up a new bar or quantum board light with a dimmer I wonder how much light is actually hitting my plants.
Yeah, there are PAR maps on the cut sheets, but I imagine that they are all rated/measured at 100% dial setting.
The bottom line is that the documentation from the manufacturer is useless to me when they list light intensity 24 inches from the canopy when there is no room in my tent to allow that kind of distance.
I don’t want to drop $600 US on a light meter after dropping that kind of coin or more on my fancy bar array, so what is a small grower to do?
If I run it too high, my tops burn and foxtail; if I run it too low the tops wind up larfy an loose.
I have been using a little bluetooth box for the last year to help dialing this in.
The software is a cludge, I do not like their EULA, and it is a pain to synchronize every time I use it, but I do find it to be a really useful gizmo.
PPF Meter from amazon
I haven’t verified any readings with higher end devices, but I trust it enough to dial down my VEG space to save wasted wattage, and keep from baking the tops of flowering plants.(Although I am pretty sure I burnt the tops of my last run, but that was not due to this tool.)
You can rent them.
I don’t dim for these reasons.
I keep beating up my local grow shop to lend the higher end ones out on a tool lease type arrangement to no avail, but I guess the regular buyer of a $1600 Gravita light already owns a $600 Apgee meter.
Just looks like a Lux meter with a converter in the app, didn’t notice anything about the spectral curve that sensor actually measures, plus needing to connect to the internet to use…
A simple Lux meter will work mine was $20, heck even a phone app based one to a degree it’s just not as accurate but it will be in straight comparison wise as light at “blank” level ones plants are good then that level can be repeated.
Download the PhoTone app for your phone!
It is free for the basics, works well for both PPFD and DLI measurements for LED lights.
Seedlings: 100 - 300 PPFD,
Veg: 300 - 600
Flower: 600 - 900
-Grouchy
check out the phantom photobio par meter. think i got mine for 150ish
a dude on riu did a side by side with one of these and an apogee meter and the results were consistently within 10 umol of each other
What I use calibrated to a 500 buck meter it’s within 1.5 percent
On my iPhone it is very accurate
I use one of these and it works great for a good price.
https://www.phantombio.com/products/controllers/product/photobio-advanced-quantum-par-meter
I recently got that app… thanks for the values!
@justdrew meant to show you that app but we got sidetracked.
Great input folks!
Really constructive discussion!
Do people still use this? I’ve got a couple of.vivarspectra 1500 pros And I’m trying to figure out din and distant settings. Any recommendations? I’m not against buying anything.
I have an iPhone 13 if that helps no special lens or anything.
Pho tone app good enough for me
I never overthink it.
The back of the hand common sense method
Works great.
But I found the manufacturer guide lines to be good
18 inch above canopy, granted I use "affordable "
Lights, for something shooting out more
The back of the hand serves a man well.
So I’m guessing you just run 100% at all times and adjust for height?
The plants are wilting… Leaves heavily curled over, stiff and dry like sandpaper, which is why I’m questioning it… had the 150w light at about 12 inches 50% dim and they aren’t happy. Backed it up to about 17.5 inch last night… waiting another day to water and I’m hoping they pull out of it
I’m trying this Photone app, but it wants me to pay for LED light spectrum. This is my first grow in over eight years so I’m hoping just get to the point where I can read the plants but some sort of guide would be nice. I guess I’ll go with the 18 inch rule… Not sure what the dim is for that though.
This has some good info.
That was with a different light. I dim with my new light.
Get Photone.
Forget about the back of the hand. I’ll burn my plants with light before they burn from heat.