Devastation happened overnight.

[Hawkins]

This plant was fine yesterday, no signs of anything wrong, and today this?
 
Also something going on here I think.

 
The top one was about 3-5 inches from the lights(T8), the bottom wasn't under any lights. Any ideas whats going on here?

 

[Edmick]

What are you using for nutrients?

 

[Hawkins]

What are you using for nutrients?

 

3/4 strength standard MiracleGro, with a little calcium concentrate.

 

[Edmick]

 
3/4 strength standard MiracleGro, with a little calcium concentrate.

How often?

 

[Edmick]

And they haven't been in direct sun at all? My guess is either nutrient burn or sun scald

 

[luvmesump3pp3rz]

this is all just my opinion but such young plants probably don`t need any fertilizing. i use nutes sparingly once they are outside and in containers or in the ground. this may not have any bearing on what is going on with your plants. just thought i would put this out there. 

 

[Hawkins]

How often?

 
Once a week.
 

 

[Hawkins]

And they haven't been in direct sun at all? My guess is either nutrient burn or sun scald

 

No sun at all, all 6500k lights, that were actually too high for these. Also the soil is full of perlite, so it drains very quickly which is why I fertilize weekly.

 

[Hawkins]

this is all just my opinion but such young plants probably don`t need any fertilizing. i use nutes sparingly once they are outside and in containers or in the ground. this may not have any bearing on what is going on with your plants. just thought i would put this out there. 

 

The soil doens't have much in it, so it's only getting what I add to it. Plus it definitely helps speed up growth.

 

[Edmick]

I'm thinking that 3/4 strength miracle grow is still too strong for a plant that size. Don't add any nutes for 2 weeks and take it easy on watering. They should be fine. They don't look "terminal" yet so I think they'll be fine.

 

[DWB]

This is what sun scald looks like.
 

 

[ShowMeDaSauce]

Regular Miracle Grow 24-8-16 is really strong stuff. Even at 1/3rd strength its pretty high for young plants. Use something really mild like GNS17 Grow 3-1-2 at half strength or less. Better yet a weak kelp based solution.

 

[solid7]

Ouch, over fert, no doubt...