Okay, I'm back.

Interesting... that site (groweeedeasy.com) is what I used for the basis for my first grow, still in progress. This was my beginning: Easy Beginner Grow Cannabis Guide w/ CFL Grow Lights | How to Grow Marijuana | Grow Weed Easy

I came HERE because I needed to know more. Not slamming sites or anything (honest). And I do like the coco/perlite approach. But, I dunno... On the link you posted, the growweedeasy folks use this as a test for too much light:

Back of Your Hand Test - For MH, HPS, CFLs and T5 grow lights

Set up your grow lights and turn them on (make sure they've had time to warm up)
Gently place your hand - palm down - right above the tallest part of your plant
Wait 10-30 seconds
If the heat coming from the light feels too warm for your hand, then it's going to be too much light for your cannabis.
I'm here to tell ya... That ain't a light test, it's a heat test. And there is nothing magical about LEDs -- the heat they produce (almost none) and the color temperature is all that matters to the plant. Er, well, unless someone proves otherwise, I guess. (Gotta leave the doors open; ya never know, right? Maybe LED's have a 3rd dimension?)

Not jumpin your shit here, but it sounds like snake oil.