Odd rust colored spotting starts second week of flower

[Rupert421]

Hey all!
Have had some odd rust colored spotting for the last several grows (happens in both hydroponic and soil) that starts usually the second or third week into flower. I have two different tents with different setups, and both have been doing this. The condition gets worse and by the time flowing is finished the leaves looks rough and burnt almost. Here are several pictures attached from the start to several weeks into flower. I can update as things worsen. Any and all help is greatly appreciated!

Green Crack Fem
DWC
Advanced nutrients (ph perfect, but still adjust to 5.8)
600W HPS
Temps with light in are around 76*-78*
Temps with light off are 68* +/-
Change solution every four days and flush the medium before adding nute solution. Tried CalMag, adjusting PH but can’t seem to lick it..
Haven’t had this issue that I remember but seems to be consistent lately.. been growing outdoor for 15+ years and indoor about 10, so not necessarily a rookie grower.

 

[JohnBlazr]

I am a rookie, but thanks for posting , maybe I can learn something. @Imzzaudae ^? @Captspaulding could maybe take a look.

 

[LoveGrowingIt]

@Rupert421 - Welcome to the farm!

It looks like you might have a spider mite infestation. I usually think calcium deficiency when someone mentions rust-colored spotting, but the pattern of the dots looks like spider mite damage. Look at the bottom of a leaf and look for mites, webbing or eggs. I use a jeweler's loupe to see them.

 

[Rupert421]

Hey man,
Ok I’ll check for that when the light kicks on later today.. I do treat weekly with Trifecta Crop Control that’s suppose to treat mold, pests and mildew but will for sure check.. did I mention none of this is happening during veg?? Only about two weeks into flowering and worsens.
Thanks for your reply!!

 

[Rupert421]

Here is a picture of what it looks like at harvest.. from roughly six months ago.. almost looks like a nute burn… or things are too hot…
Again all help is greatly appreciated!!

 

[HerbalEdu]

i would have said calcium deficiency or manganese toxicity due to heat stress but you seem to have the temperature under control with the hps ...

 

[LoveGrowingIt]

Hey man,
Ok I’ll check for that when the light kicks on later today.. I do treat weekly with Trifecta Crop Control that’s suppose to treat mold, pests and mildew but will for sure check.. did I mention none of this is happening during veg?? Only about two weeks into flowering and worsens.
Thanks for your reply!!

I'm not familiar with that product. Do you spray the bottoms of the leaves? That's where spider mites live. They thrive in hot and dry conditions, like late summer. A problem with spider mites is that they can evolve and adapt, so more than one method of killing them is needed.

Here is a picture of what it looks like at harvest.. from roughly six months ago.. almost looks like a nute burn… or things are too hot…
Again all help is greatly appreciated!!

You may have more than one issue. I agree that the second picture could be a nutrient problem. I can't see it very well, though. Several things can cause leaf tip necrosis.

 

[Rupert421]

Hey Herb,
Yeah man.. I’ve tried bumping that up (calmag) intake with no result.. I won’t lie my temps have claimed a little higher maybe to 80* on occasion but I’ve got fans blowing from under and on top of the plant, with the exhaust fan on full bore to help extinguish any hot air. Thank you for the reply!

 

[Rupert421]

LGI,
Thanks for the reply man! I do spray top and bottom of the foliage after a light cycle.. any suggestions on products?? Let me search for a better picture.

 

[Rupert421]

Maybe a little better..

 

[LoveGrowingIt]

80º isn't too hot. That's about where I run my tents.

I have seen leaf tip necrosis from wind damage from the fans. I think it dries the leaves too much. During my last grow, I noticed leaves near the fan had that problem. I changed the fans and that fixed it. I'm not sure if that's what's happening here. It's just a thought.

 

[Rupert421]

And the brown leaves are total crisp.. wisp away in any breeze or being touched..

 

[Rupert421]

Totally LGI, things are a little tight in there and has crossed my mind of wind burn.. just the spotting throws me off.. thanks again

 

[HerbalEdu]

i had manganese toxicity with some strains around 100° 104° with the hps in summer (switched to led since), 80 is more than fine

 

[Rupert421]

Toxicity as in too much?? Would that burn the leaves with a higher temp?

 

[HerbalEdu]

yeah temperature change the leaves metabolism some fonction could be altered like the way they process manganese creating excess symptoms.

 

[Rupert421]

Hmmmmm…. You’ve got the gears turning now! Would it make sense certain strains can handle the heat better than others, and have no symptoms.. with others ending up being a total crisp.. I’ve been wanting to switch to led for some time now.. maybe after this run would be a good chance.

 

[HerbalEdu]

Another thing i could think is your leaves look a lot dark green like high on nitrogen but same it seem you've not changed that much your feeding habits over the last grows, also what's weird is it happen indifferently in soil and hydro ...

 

[Rupert421]

Plus a new fan set up maybe..

 

[HerbalEdu]

not only strains but sometime even phenotype within the same strains don't react the same to environnemental conditions. but at 80 your fine, below 96 cannabis seem to do it pretty well from my experience