New grower, stumped on what this could be. Yellowing/rust spot appearance

[ItzSticky]

Hello AFN,

I’ve been brainstorming what deficiency could be causing the yellow spotting and brown spots similar to rust marks.
I’m pretty stumped and don't want to assume what it is.
Im thinking its either some mildew issue, cal-mag, or a PH lockout of some sort.

I have a journal that i’ve been posting concerns and what i’ve done so far if interested in helping:

https://www.autoflower.org/threads/...-a-4x4-tent-new-grower-advice-welcomed.85704/

 

[namvet25]

https://www.autoflower.org/threads/...ill-out-first-with-the-data-that-matta.45991/ Fill this out please.

 

[ItzSticky]

Problem: (brief description)
Described above.

-Medium/grow method: soil; soilless-- coco, or peat based like Promix, etc. (please provide the actual product name);
Soil - Fox Farm Ocean Forest.

-Feed and supplements used:
I have been watering about 4-8 cups every 4-5 days.
I’ve been adding 1 ML silica, and mosquito dunks to water.
Water is filtered using a boogey blue filter to eliminate chlorides and chloramines

-Strain and age
Crop King breeder - Gorilla Cake and Early Miss
approximately 4 weeks old

-Climate: night and day ambient T and RH%; res' temperatures; any extremes in T/RH% exposure
Indoor in a tent. On a 18/6 light cycle. Temps with lights on stays around 77-79F when lights are off its around 73-74. RH stays between 55%-65%

- Light used: HID, LED, COB, combo of,... wattage; light cycle hours (20/4, 18/6 , etc.); distance to tops....
LED California light works 550
Sits about 2 feet above canopy
18/6 light cycle

-Additional info: How long have the plants been affected?...How fast did symptoms appear?... Anything else you think might be relevant..
I want to say i started noticing symptoms around week 3. Currently have been fighting fungus gnats.

--Pictures including WHOLE PLANT PICS, and troubled leaves.. use normal light or flash as other light sources ruin color rendering, critical for diagnostics!
Pictures above.

 

[namvet25]

I have to go somware so ill be back.I'll see if i can get somone to help.

 

[namvet25]

Plant is too young to have any deficencies and it looks ok.Next time you water give her some calmag 1tsp per gal

 

[ItzSticky]

Plant is too young to have any deficencies and it looks ok.Next time you water give her some calmag 1tsp per gal

Thank you Nam!
The first time i realized some light yellow/brown coloration i fed with some FF Grow big 6-4-4 nute at a 1/4 strength that they recommend on week 3.
Thought maybe it was nitrogen deficiency.
Doesn’t seem like it did much. Maybe even got a little more browning.
Led me to think maybe my PH was off, causing lockout.
I was going to do a swirl test today to check PH of my soil.

I’ll give them some cal-mag next feeding and see how they like it.
Thanks again!

 

[ItzSticky]

With the slurry test i had a PH of 6.18 and the other 6.07