I'm not sure because I honestly don't trust any phone app readings. Get something like this:
You want to run you plants pretty hard and if you are actually at 30klx then I'd be running those lighting levels higher. Don't go below 40klx.
I actually was meaning T5 type LED strips but I was high.
I’m retrofitting an old Phototron grow chamber with LED and ordered these Plant Grow Light 6 Packs T5 Samsung&Full Spectrum 3500K 6500K&Red LED with Auto Cycle Timer 3/6/12Hours Dual Channel 4 Brightness Level Growing Lamp for Indoor Plants from Seeding to Harvest https://www.amazon.com/dp/B086W1KK2B/ref=cm_sw_r_cp_api_glt_fabc_J2PSRKW1B0XF0V0V6ZVP
It will have 6 strips surrounding a vertical chamber about 20” in diameter. Is that enough or too much? I ordered the LUX meter you recommended. Do I shoot for 75k LUX in the center?
This is a good practical book made for the beginner:
https://www.amazon.com/Practical-Electronics-Inventors-Third-Scherz/dp/0071771336
This is the "bible":
https://www.amazon.com/Art-Electronics-Paul-Horowitz/dp/0521370957