Necrotic spots on fan leaves?

[Cwmoore577]

To give some detail of my setup...
I have 2 autoflowers (Zkittlez and GelatOG) in a 2x4 tent. Both are week 5 veg, showing pistils.
My light is the Series 2+ Red spec 250w from BudgetLED and currently have it dimmed to about 80% maybe.
Temps steady at 75-80°F, Humidity a bit low usually high 40s, low 50s.
My medium is Royal Gold Tupur mix (coco based) in 3 gallon smart pots.

For the last week or so I’ve started using H3ad’s modified Lucas formula although instead of the 6ml/9ml and 1g Epsom per gallon I started them at lower EC to see how they would do with the switch.
So I’ve been using this:
0.5ml Stout MSA (mono-silicic acid)
1ml Calmag (2% N, 3.5% Ca, 1% Mg)
0.5g Epsom salt
3ml GH FloraMicro
4.5ml GH FloraBloom

which gives me around 0.7 ec and 500ppm and I pH to around 5.9-6.0 mostly.
I use ro water and water twice daily on a timer with my dripper system. I handwater once every 4-5 days as well to try to make sure everything gets saturated.

Yesterday, I also added photosynthesis plus to my res at 15ml/gal to try and prevent harmful bacteria in the res.

here’s some pictures of the damage..

 

[Cwmoore577]

Here’s the whole plant

Some drooping as well

there are a spot or two on my other (gelatog) but it looks healthier as far as drooping and leaf color..

 

[Bnelly]

I too am interested in seeing what this ends up being. Let me see if I can find the link, someone had a similar color that was a mold or fungus and it was called rust I believe

 

[Bnelly]

Help, please! Have never seen this before

Hi Folks, I’ve never seen this before. The top bud of the branch has turned brown and pretty crispy. He plant is an L.A. Confidential that is 5 weeks into flower. This happened quickly as the plant looked fine 2 days ago. Used my loupe to check for critters as we have had spider mites In the...

www.420magazine.com

It looks a little bit different to me but maybe it provides help for you. Cheers

 

[BooMtoLate]

New growth seems unaffected.

 

[Bnelly]

New growth seems unaffected.

Glad someone more experienced chimed in.

I'm trying to think what it could be. Other than droopiness and spots they look pretty healthy to me.

Looking forward to seeing the diagnosis

 

[Cwmoore577]

New growth seems unaffected.

Yes but it’s popped up in the last few days. Haven’t noticed it this bad until today and I check them over at least once daily.

Glad someone more experienced chimed in.

I'm trying to think what it could be. Other than droopiness and spots they look pretty healthy to me.

Looking forward to seeing the diagnosis

I hope it isn’t the rust fungus. I googled it and doesn’t look like those photos. I’m not sure what causes rust fungus but I did cut up wired clothes hangers to LST them. Unsure if literal rust has anything to do with it, just giving more information.

From looking around, to me it looks like what pH fluctuations would cause but I measure my runoff often and haven’t noticed anything off.
My last measurement was pH 5.88, 0.53 EC and 380ppm.

 

[Bnelly]

I'm in the midst of fixing some ph and overwatering issue too, it really hurt my seedlings, but luckily they're starting to recover. I'm quickly learning that Ph is at the forefront of many problems. Best of luck!

 

[BooMtoLate]

How big is your res and how much cal mag are you adding? Almost looks like a defenicy.

 

[BooMtoLate]

I have some spots as well, kinda looks similar

 

[Cwmoore577]

How big is your res and how much cal mag are you adding? Almost looks like a defenicy.

My res is like 17 or 18 gallons but I usually only have 5-8 gallons at most in there at one time to prevent siphoning. I try to keep it close to what the formula is, which is 1g Epsom per gallon. That amounts to less than a teaspoon per 5 gallons. Although bc I try to use my calmag as well, ive been using 1ml/gal CalMag and 0.5g Epsom salt.

 

[Cwmoore577]

I have some spots as well, kinda looks similar

Yours looks more like classic cal deficiency. Mine have an almost off white color to them, some a bit orange-ish.

 

[Cwmoore577]

Took a few leaves to see if it’s still progressing and it is. More spots over night.