help needed please

Hi everyone im new to the forum and to growing so please go light on me im 4 weeks on my flower cycle im using a 600 watt hps light in aero wings box 6inch rvk fan as my intake, and im using a 5inch tt as my out take my tent size is 160 hight 120 wide 65 depth so as u can see im limited to space my temps are 70f with the light on and humidity is between 50/60, when the light is off my temp is 65f and humidity 70/80 i now its high but i cant get it down, the way ive been feeding them 12ml of house & garden a & 12ml of house & garden b 2ml super thrive, started 10ml house & garden multi zyme aswell 2 weeks ago mixed into 10 litres of water i feed them every other day i give them 1-1.5 litres each ive been told to add water to the bottom tray as my roots are coming out the bottom of my pots im sure my pots are 11 litre pots im using coco premium soil. i spray the plants twice a week with nitrozyme & super mite spray here is where my problem comes a few of my bottom plant leafs are turning dark yellow colour but what could be causing this and some of my leafs are curling down cheers for the comments

Lower leaves yellow and die as the plant matures, it's normal.

Unless you start to have massive leaf die off, don't sweat it.

Take pics right when your HPS shuts off, hard for people to give you sound advice when the color of your pics is distorted by the HPS.

cheers greenlikemoney ill do that, but does my feeding sound ok also whats with the leafs curling cheers