4th week flowering Brown spots MANY CLEAR PICS!!! HELP!!!!!!!+rep

Hey guys here i have white widow about 4 feet tall in her 4th week of flowering watering every other day she looks great but shes slowly developing brownish spots with yellowing of the leaves they all looked fine when in veg but ive grown before and these happened to me in flowering both times i use the fox farm trio as welll as fox farm happy frog soil i water the plant every other day using half strenght nutes every other watering they are under a 400w hps temps are about 80-85 day 60-70 night they are a little cramped in there i have 5 plants and so far only 2 of them are showing these symptoms they are close to the light but its in a cool tube and i can hold my hand under it all day the leaves sometimes curl up and sometimescurl down im clueless any help from the pics?

looks like a little bit of nute burn..

you say your feeding them every day, if so don't. back off the feeding to every 3 to 4 days.

i feed every other day with half strenght meaning nutes then water then nutes then water and so on

Sometimes (especially with a finicky strain), I will only feed every other watering. Or take your nute mix down to a half or a quarter....Less is more with nutes IMO. Remember also, even hippy run nutrient companies want to make a profit. Use the "feeding schedule" they recommend as a loose guideline. They want you to use up their "super-mega-ultra-candy-purple-flower-hardening-silica blaster" and come buy more.

You said you were 4 weeks into flowering? where did you take those leave cuts from? If your using a higher ratio of P in your NPK already it could be a lack of nitrogen, and some of the lower leaves are dying off prematurely...

i took them from the middle the symptoms do not affect the newer growth just the older leaves

could be a p defiency but a pick of the whole plant would give a better idea, also did you giive the plants a flush yet as there could be a build up of salts in the soil aswell. a p[ick of the whole plant would make it easeier to identify problem.
lu