Début de carence ?

looks more like an excess to me then a deficiency. Temps are good and lighitng schedule looks fine as well. No ida what cork soil is "coir?" but might be a translation error.

Now you have give nutes just keep an eye on her.. Not to be a bearer of bad news but those plants are way small. Maybe for your first go you should do less plants and only 1 strain to help with the learning.. More plants doesn't necessarily mean more weed.. Good luck pal

either K def or lock