3 week old seedlings burnt tips ?

Today is week 3 for my seedling and I've noticed the tips are becoming burnt for some reason. My system is dwc and my nutes are general hydroponics flora series at 1/4 strength. My light I'm using is a galaxyhydro 300w LED hung about 3 feet from the seedling. Are they suffering from nute burn or light burn ?

it aint light burn. I'd let it be and keep an eye on the other leaves for same,
what are those little spots that cover the leaves in pic 1?

Do you spray water on your seedlings? Tips get like that when drops of water stay there for a while. Plants don't need spraying.

I believe those spots are tiny glands on the leaf @chemphlegm. See that on many of mine.

Forgive me but week 3 from sprout ? If that's correct something is wrong.

Did you ph the rock wool?

Did u mist the plant?

Maybe to much humidity/dry

That's not burn of any kind, that was the sign of an early calcium deficiency. You can tell exactly when you started feeding them , and you were probably a few days late (which also would explain the slow growth) Those leaves will continue to look worse and worse as they get larger. Don't worry about them though, as long as you're feeding them properly now all the newer foliage should be normal.