Brown spots on leaves

[Blazed227]

Ok so I just noticed these spots.. dunno why they showed up.. plants have all been really healthy.. I just switched to flower 2 days ago.. now I got spots showing up.. fml... anyway what u guys think it could b from.. looks like a phosphorus def.. or maybe the ph is outta wack.. cause there is no way it's a def.. also how much do you guys feed your girls.. I used to slowly dump a gallon of water/5 gal pot.. an used to have a good bit of run off.. now I dump a gallon an not 1 drop comes out... the past 2 times... Maybe I should up it to a gallon an a half? Could the spots be from the salt build ups because they haven't been having any runoff... here's pics of the spots.. sorry the hps is still on.. didn't have time to unplug it then let it cool down an all that.. but the color is good.. besides the spots an yhe yellowing around the spots...heres some pics

 

[Tika]

What kind of pots are you using? I use 5 gal smart pots ( Coco& perlite)and I found into the flower period they used 1.5 gal water/ nutes. Soon graduated to 2 gal water/nutes to get runoff. Heading into week 7 of flower I water/ feed 2x a week or every 4 days.
The pH is vital to your plants: I am a BlueLab pH pen fan. That the pen and 3 solutions run about 100$ is WELL worth it.
altho I don't know what is causing your spots I would guess pH. Then check your lights.

 

[Bikerstonrr]

Can't really tell without checking ph first. www.growweedeasy.com/ph

 

[Blazed227]

Well ph was good 6.4 I think somethin may have dripped on the leaves maybe nute solution.. I flushed them out real good with 2 gallons each then fed to get any salt build up out.. an now there back to looking great an no spots are coming back so. I think all is good ,thanks for the replies!