when shall i add my nutes plants 17 days old

going to use dutch pro nutes, not sure when to add them, pics so far of my plants 17 days old:
sleestack skunk

What's in your mix? Any nutes?

I'm using this soil light mix http://www.hydrohobby.co.uk/50l-biobizz-light-mix.html

and ive bought dutch pro bloom and dutch pro arde, used for veg

still havent used any yet plants looking kinda healthy