Some leaves are yellow? whats wrongg

SO thats my baby!! og kush , shes been growing for about 2-3 weeks and recently one leave tip turned yellow n curled up (picture below)

And its not just on that leave its always on the back side
(i kno its blurry but u can see it aha)

I feed it nutes but only the amount for a seedling which is only 1 tablespoon per gallon, but i only gave it nutes once and that was a while back. Any suggestions on whats going on?
THANKS!!

...what's the soil your using?

One tablespoon of Fox Farm could be too much. What nute are you using. Looks like PH to me though.

Looks like too much nutes to me. The leaves are real dark green but could be the strain.

The nutes + whatever is in the soil (potting mix, etc) could be the culprit. Check PH, maybe just distilled water for a week or so

The soil is Fox Farms organic soil. and the nutes i bought as a trio pack of Fox farms Big Bloom, Grow Big Soil, and Tiger Bloom but i only used the Organic feed which is Big Bloom. and i went off the directions of how much to use off the back of the bottle.

Im not sure what my PH is i dont got a ph tester.

I just watered her today to.