Reddish spots on leaves and veins, help please, pictures

View attachment 1791652View attachment 1791650View attachment 1791649View attachment 1791647View attachment 1791645View attachment 1791644

21days in flowering. The leaves pictures are the top of the plants. Made a big mistake spraying for PM and bugs while light was on (1000 HPS). PM started at 10 days in flowering (high humidity, bought a dehumidifier since and RH is at 45 to 50 %, temp 75 to 85)
Now i wonder if there are other issues that are affecting my plants, flushed them a week ago, last feed 4 days ago, yesterday RO + CALMAG 1 liter per plant. leaves are not as green as they used to be, somewhat pale with whitish spots (could it be after-effect from the burn) otherwise plants seem to be ok at the tops (leaves up). Let me know what you think and if you need more information to diagnose, thank you in advance.

Sounds like you are on top of things, If you are using r/o then I would use calmag more often then just in flush. Like every other feeding.
I'm sure you know when a plant cant get the nutrients it needs from the medium it will use the stored nutrients in its leaf. That happens naturally in flower starting with the older leaf. That could be whats happening or its possible pH is not correct and the plant cant use its available nutrients. I noticed some of the leaf stem is red, that's a sign of stress. Hows the night temps?

Temp is 70 to 75 at night with dehimidifier/fan/oscilatings/heater- 75 to 85 during the day with dehumidifier/light/fan/oscilatings, light 2 feet from top of the highest plants (which are doing fine) lower plants are the problem.
I assume i made a mistake spraying for pm and bugs while lights were on, am i right ?
PH could be the right call i will check it out (need to buy something better than what i have to check PH, i got a lame two prong stick in thing)
I will follow your advice on calmag + Ro, thank you cruzer.
The west side of santa cruz is always in the fog, super high humidity and that sucks, LoL.

Its purple kush am growing, maybe that is why the stems are reddish ! not sure but might as well mention it. Weird tho out of 12 plants, 10 are short and the other 2 taller and not as bushy, LoL maybe they sold me two different strains and not all purple kush ? but from what am seeing the taller ones are the way i would/will go since they are healthy and starting to look nice.

Well the deal with spraying then lights on is the little drops can magnify the light and burn leaf. The pic didnt look like a burn more like a deficiency.
Yeah, r/o removes all the calcium and magnesium along with everything else, calmag a must for hydro grows. That little pH meter with the two prongs isnt very accurate. its best to get a pH pen and test your water. be sure to do it after you add nutes too.