Help a brother

Hello lads i'm having some trouble (again) with some of my plants. Two of them to be precise. First it was just one now there are two. They are in 30 gal holes, filled with biobizz all mix soil; never got fed, only thing they got is rain water. Temperatures are constant 20-30° C. Anybody ever seen this ?

nute def?

poss

http://www.growweedeasy.com/sites/growweedeasy.com/files/zinc-deficiency-marijuana.jpeg

more
http://www.growweedeasy.com/marijuana-symptoms

thanks gioua i think it might be the first one. maybe the rain water is acidic or something and this changes the pH of the soil and elements are being locked out. I'll feed them 25L of water with 6.5 pH and some fert rich in micro elements. Thanks a lot dude