Yellowing/rusting on purple kush? any ideas?

[karambitkustom1322]

Ok guys,
I posted a log on here few days back of my plants at day 44 from seed, althought the buds seem to be growing alright and visible crystals already there is allot of yellowing and some rust type spots on the purple kush, and on one of the little cheese's...
After looking over the sick plant pics on here to try and diagnose the problem, I am just not sure what the cause is?!
I am using 4ml of Cal Mag plus and have seen a little improvement I think, but wana make sure theres not something I am missing! Thanks for any help guys
Pics included in post!

 

[namvet25]

Is that cal/mag dose per gallon? What kind of lights are you using?What nutes are you feeding now?

 

[karambitkustom1322]

The 4ML is per gallon, I have been told to up it to 5ml per gallon so might try that...
Using a 90 watt led ufo made in USA, not a cheap chinese one lol,,I have done a few grows with this light and it works just fine for producing a nice harvest every time, I mean I am using just a GL40 tent, so not very big but about the biggest led you can fit in it lol..
I have been using fox farm open sesseme so far, only used twice and small dose mixed with the cal mag and Mammoth P...

Is that cal/mag dose per gallon? What kind of lights are you using?What nutes are you feeding now?

 

[Waira]

Karam'-- advanced symptoms here, likely more than one issue happening,... we need a soil pH for sure! ...the overall yellowing and necrotic patches are separate things,... We need to determine if you have a lack-of type defc.'s, or a pH lock-out of them, meaning they're present, but rendered unavailable by off pH,... The dead spots look mostly like P defc. to me, but Ca defc. can more atypically present something similar as well,... The yellowing is more generic, but the fact that it's hitting high and low, makes me think possible S defc., but that's hard to call until an accurate pH test is done,... Unless you have a quality soil pH probe, for direct in-soil testing (Accurate 8 makes a good one), you'll have to do the less desirable run-off testing; here's a link to an improved method for this, follow directions carefully, and don't forget to do the simple calculation at the end... measuring straight run-off directly doesn't give an accurate pH.... ( https://www.autoflower.org/threads/...-testing-and-ph-estimation.41733/#post-928975 ).... let us know what you get!