nute burn or too much light or both?

I'm a noob and I grew her from seedling. She about 4 weeks. She was looking good until I saw those to spots then I thought it would be a good idea to get a water bottle and spray with fert mix the I use. I'm using mg soil and mg fert mix 20-20-20 the light I'm using is a cfl 27k 2850 lumen 42 watt bulb about 4" away.
Can someone help this noob.

Nutrient burn typically starts from the tip and edges and works inwards.

For example this is sun burn


And this is nutrient burn
View attachment 2810420

If its only one small spot on one leaf don't worry much about it. (your temps might have gotten a little high, or the leaf might have come in contact with a surface that is really hot and burned the plant etc etc.)
Unless it starts to spread.