weird brown spots

[webanator]

hello all growers
I'm on week 3 of flowering using super soil, 600 watt led light, humidity at 45%, temperature 23c, water ph'd to 6.5
a few middle fan leaves started developing weird brow spots
please help

 

[Gluteous]

Should definitely start here: https://www.growweedeasy.com/cannabis-symptoms-pictures

 

[OlderNOTwiser]

My guess is this: https://www.growweedeasy.com/cannabis-plant-problems/phosphorus-deficiency I don't use a super soil so IF this looks about right others will need to chime in on a resolution for your medium.