You’re looking for a Daily Light Integral (DLI) Chart That will measure for PPFD, which I have included at the bottom of this post.
( quick disclaimer I mean no offense when I provide definitions and/or formulas below; I assume you’re a rather smart person with a sound understanding of how this all works, but I don’t want to ramble off a bunch of crap without explaining myself. Plus, it may help others reading this post who may not know. I certainly don’t mean to patronize you, so I hope it doesn’t come across as such. )
DLI measures the actual number of photons (specifically, photons capable of being used in the photosynthetic process*) within a given area per 24 hours.
Photosynthetic Photon Flux Density measures the amount of photons packed into your light and is measured in micromoles per meter squared per second: umol/m2/s
The packaging for your light should have some sort of information regarding the PPFD of your light.
DLI calculation formula is:
DLI = (PPFD) x (3600 x photoperiod) / 1.000.000 – moles/m2/day
(3600 is how many seconds in an hour; 1.000.000 = micromoles / mole)
HOWEVER - we’re getting monster specific here and isn’t exactly necessary. Your light should be able to generally dim the intensity. For your infant seedlings you should be at 15/30/30. As they become a wee bit more established, like after they’ve popped their cotyledons and have their first real leaves, you can increase to 30/60/60. You should have your light minimum 6" from your babies but if they’re getting too hot you can lift the light. Try not to go higher than 12" though because they could stretch and that sucks. Obv.
I hope this helps out a bit. You really know how to test a girl’s long forgotten physics this early in the day!! Dayum!!
Let me know if I can help another way or if I didn’t address your issues.
*photosynthetically capable photons are photons anywhere in the range of four to seven hundred nm