low leaves yellow, new leaves growing really tiny!

i dunno what's this problem... it's the second week of flowering, im giving it some nutrients, it's on prepared soil with perlite.

im using 15-15-15 nuts but it never show this problem.

help, please, thanks!

Its normal, I guess this is your first grow.
This is when the magic happens. BTW you should not use 15-15-15
Your plant is going into flower and will require less Nitrogen. Look into it.

your nutrient is just fine, you aren't controlling the environment too much to start worrying about that.

read into plant problem due to over-watering, this is exactly what it looks like to me but i can't tell you what to do off one picture, read the forum about plant problems or google it it's everywhere.

over-watering can cause that 'exhausted' drooping look, and inefficiency in allocation of nutrient and light causing 'nitrogen-like' deficiency in new growth.

but a moisture meter 6$, weed needs soil to dry out thoroughly and then watered thoroughly.

bump up those phosphates.... but that's not your problem, well you don't really have problem at all.

It's not going to produce any more large fan leaves and some will yellow starting at the bottom, this is just what happens during flowering. Your plant is focusing on it's flowers - not it's leaves....

they look ok to me, just be sure to take down the nitrogen which is required in higher doses during veg and bump up the phosphorus during flowering. you will always get leaves yellowing and drying up towards the bottom, but if it goes above the bottom couple nodes it could be over nuting....or a number or other things lol