Dark spots and some rusty spots... calcium or pm?

oill

Well-Known Member
Week 6
Led grow
In coco
Ph 5.9
Ec 1.8
Fed daily til run off
Temps now 25c

Increased heat a few days ago and just noticed this on one plant... everything else looks good.

Given the increased temps powerful leds and coco grow I'm thinking this is calmag def.... but could also be fungus of some type...

Spots are starting dark green before going rusty.... ahhh the dreaded rust.
 

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oill

Well-Known Member
Then its not a vpd issue,RO water?
Nope... hard water.... using hydroponic research veg + bloom and shine.

I did also add a molasses and guano tea about a week ago.

My theories are...
Light is too close... I moved it down a few days back
Change in temps made it warmer
Phosphorus being activated from the guano leading p overdose
Maybe molasses fucking with the ph.


I'm thinking of flushing this one plant with a balanced buy weak nutrient solution and making sure I add a little calmag

What ya think?
 

myke

Well-Known Member
Nope... hard water.... using hydroponic research veg + bloom and shine.

I did also add a molasses and guano tea about a week ago.

My theories are...
Light is too close... I moved it down a few days back
Change in temps made it warmer
Phosphorus being activated from the guano leading p overdose
Maybe molasses fucking with the ph.


I'm thinking of flushing this one plant with a balanced buy weak nutrient solution and making sure I add a little calmag

What ya think?
Molasses? Crazy stuff there.Yup ,fucks with pH.Ive only used it in organic and was terrible never used it again.
Seems right,Ca deficiency most likely something you've done.
 

oill

Well-Known Member
Molasses? Crazy stuff there.Yup ,fucks with pH.Ive only used it in organic and was terrible never used it again.
Seems right,Ca deficiency most likely something you've done.
Glad it's only one of 9... touch wood....

Hopefully can sort it with a bit of a flush.
 

oill

Well-Known Member
why increase heat? if that's the one thing you changed, then the spot show up, maybe that's the problem.
It had wondered downwards due to outdoor weather... so I increased the heater power.... not massive changes tho.... was getting to 21/22.... now its 25ish
 

polishpollack

Well-Known Member
no but under warm light maybe the compounds on the leaf surface. if it's not nutrient issue or a bug issue, it might be temp.
 

oill

Well-Known Member
Molasses? Crazy stuff there.Yup ,fucks with pH.Ive only used it in organic and was terrible never used it again.
Seems right,Ca deficiency most likely something you've done.
no but under warm light maybe the compounds on the leaf surface. if it's not nutrient issue or a bug issue, it might be temp.
I just recalibrate my ph pen and my nutes are way too low.... the number if times I've said to people calibrate calibrate calibrate... ffs....

I'm trying to bring it back up but it's taking a lot of liquid to do it. Keep feeding ph6 and it's still coming out at 5.1 ish. I'm guessing this is coz I was too acidic with the nutes and probably the molasses. Gonna be feeding til run off this week every time to try and correct this.
 
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