First time, young plant yellow leaves

Hi all, new to this whole thing. There is this young plant, its growing okay but the leaves seem to pointing upwards at the sides and are turning slightly yellow, new leaves that have starting growing seem a lot greener though. I think it is ill, any help would be appreciated thanks. Set up is 400w HPS in closet, Indoor mixed seeds.

Looks like a nitrogen deficiency. What are you growing in?

It's Westland Multi-Purpose Compost, what would be the best way to replace nitrogen if nitrogen deficiency was the case? i killed a plant accidentally with an indoor plant liquid fertilizer NPK 7+6+6 last week...not having much luck but learning as I go!

You gotta cut that compost with something, soil, peat, or coco. There is probably some kind of nute lockout going on. I suggest you find a more suitable growing medium.

aaah okay, thanks! will try sort that out just now

I have had problems in the past using Miracle Grow with seedlings. After the for set of leaves they just stop groing and turn a little yellow. Eventually they pull through it but it took them almost two weeks to start growing again. I use a custom little recipie for my seedlings an vegging. I use

3 parts Peat moss or Hyponex (depending on preference)
3 parts Perlite
1/2 part Miracle Grow
1/2 part Blood Meal

It works great for my babies. Just enough nutes tyo get them going.

ah excellent cheers, i think i shall try that with another seed and see how it goes

I have a young plant to and my plants lower leaves are light yellow?