I have read about meters to test ppm on LED lighting. I am not exactly sure what is happening here. I have a sf1000 and vs1000 together in my 3 x 3 tent. Both have dials for light intensity, but I am not sure how to adjust them for brightness. I would like to be able to test this set up but don’t have a meter. Can anyone help by pointing me toward a decent meter? I can’ spend a ton of money being a disabled vet on limited income. I have seen PAR and LUX meters for sale but don’t know which one is required for testing or even what numbers to look for as to set up the lights. Can anyone explain how to set up lighting intensity in a tent? I am learning so please bear with me. Thank you for any info on testing and setting up lights. I do know about various height settings but no anything about these dials for brightness.
Follow the recommendations given by your manufacturer. In example my light is 25-30% seedling 50-75% for veg, 75-80% preflower, 80-100% flower. Hanging height will have alot more to do with your ability to control leaf temp. Have you read @Nicky DLI thread? It will help and explain how to use the photone app. Search DLI and you will find the thread.
Here’s a link to the DLI thread - it can get a little dry if you keep reading but the basics can be had in the first few posts.
There are several light meter apps you can download to your phone.
Truthfully, other than for knowledge and curiosity purposes, any sort of light monitoring of 100 watt lights is not worth the effort. If the SF1000 is at 12" its dead center PPFD is only 972. When it is hung at 18" it drops down to 549. You can not do a lot of damage to a plant with a PPFD of 549.
I like this growth stage chart from Lumi Grow
The top line Avg. Light Intesity is measured in micromoles per square meter per second (μmol·m-2·s-1) which is the long way of saying PPFD ( Photosynthetic Photon Flux Density)
What this chart is telling you is the necessary light intensity from corner to corner during flower in your 3x3 is a PPFD of 700 - 800
Again referring to the SF1000 once you move 6" off center its PAR readings drop to 775 to 640’s…
Since DLI was mentioned here is a graph of recommended DLI (daily light integral) I added the DLI calculation formulas for reference purposes
Many growers favor pushing DLI of 45 through flower until the last few weeks. This also means you need more light intensity over the grow space because there are now only 12 light hours rather than 18 during veg (typically)
Obtain a basic understanding but don’t drive yourself crazy. IMO anything from Dr Bruce Bugbee is worth watching. This one is on light
This little gem is also from LumiGrow
Thank you for the great info., I think I will follow your light schedule with the per cent values you mentioned.
UT383-BT on Amazon.
Another method (my android phone app was useless).
Calculate the math using HLG web calculators.
Third method, use seller advertisement and follow.