300w led. When is it safe to use?

[sosl0w]

 
I had 2 300w leds in there at first a foot above the plants. Had to remove one and raise the other so it was about 18" above them. Still was burning my plants. They are under a t5 now and will be going back to led in a couple weeks when I transplant to bigger pots and tent. Check my growlog for pics/info.  http://thehotpepper.com/topic/45161-sm1nts2escapes-2014-first-glog/

 
Hmm, that's surprising, I have 4 300w LED lights that I use and i start all of mine from seed right to LED. I usually start mine out at 18" as well. But the LEDs in my lights don't have lenses on them either. They are all 120 degree angle. So if your lights have lenses on them you would need to put them higher because the lenses will focus the light more and make it more intense which could be causing the burning. What lights do you have?