thats a seedling man, you definitely have a problem, try cutting a coke bottle to make a mini-humidity chamber, wait a few days to water but next water you might want to hit it with a root stim
you should look into nutes like Top-Max or Overdrive, they cause rapid cell division during flowering.. sometimes pk 13/14 isnt enough but with a bloom booster you will see you plants double in size.. alot of people recommend Black Strap Molasses too to add bulk to your crop but in my...