Clones showing burn?

Just switched my clones over from 2 T12 40w bulbs to a 900w viparspectra led and I'm starting to see burn looking marks on the leafs. I transplanted these clones from solo cups on 6/16 and their last watering was on 6/21 where I gave them 1 TSP ( quarter of the weekly recommendation, didn't wanna kill them for my first time using notes) of big bloom at a 6.3 ph. I started the led light at 20" above the plants and there was slight browning occurring. I raised the LED light to 32" before work today and I came home to multiple burnt leafs. Also the soil is looking dry so I was planning on watering them but wasn't sure if I was deficient somewhere! I've now raised the LED to 40" which is max for me at the moment. Any help would be greatly appreciated as I'm a newb! Thanks

Yeah it's just the plant had not acclimated to the light before you put it so close. It burnt at 20", but if you start at 40" or w/e and gradually lower it, it maybe able to handle 20" no problem after it's acclimated. When you first move seedlings from CFL to HPS you need to keep the HPS real high at first also, but once the plant gets used to it it's no problem.

Cool thanks!

Vpd aka vapor pressure defecit..what's ur rh%

VPD burn occurs at the tips and edges.

My Rh sits around 38% with my carbon filter running on high to cool the closet down from heat generated from led light. If I turn it down to medium my RH is about a 44% but then the heat goes up to about 89 degrees.

It's lights out right now so I turned down the carbon filter to the lowest speed to keep air movement going. Temperatures are also at 71 so nothing to cool down. My humidity should rise to 45% overnight. There was also no new burn on any leaves since raising the LED to 40". I'll update in the AM before work! Thanks for the ideas!

U may need a humidifier

Ubgont want urbtemps at 89 tho I'd keep it around 75-80 if possible those are about ideal at lights on temps about 62 at niight or 10 degrees farrenhiet cooler then day temps

Got it! Yea even after dropping my carbon filter fan down to Low the highest my humidity ever hit was 40 last night. I will look into purchasing a little humidifier for my closet. On the plus side there are no new burn marks so i think it had 99% to do with the way I introduced the light to my clones! Lesson learned!