Yellowing with brown/black rusty spots

Hello folks! Im growing under 150W HPS+50W CFL ,2 plants (ArjansHaze#3 and Kalashnikova) in 2.2 gallon pots, soil+perlite+ i added some lime.Temperatures in box are 20-22 when light is off and 25-28 when light is on.I started to fertilize 1 week before i switched to flower.Only nutrient i use is Plagron Alga Bloom (and one time i added some vitamines -bio additiv.Water PH is 6.5 from begining. I veged them for 39 days and now im in day 5 of flowering. So i noticed some yellowing under the screen with those black/brown spots on the leaves.
So im asking for opinions ,what could that be. Thnx


sorry for my bad english

Your plants look a little sad, like they've been over watered or haven't been getting enough fresh air. The second photo looks like a small baby leaf. It was probably growing in a dark area, towards the bottom, and it couldn't get to the lights and used up all it's energy. Since it's not all over your plants I wouldn't worry about it.

ok thnx for the answer.Sad look is becouse i just waterd them( they alwas look like that when waterd,and after 1 hour they dont look sad anymore).