Nute Burn/Deficiency?

[Hog_M@Gundy]

Twenty20 Muchacha 25 Days Old

Medium: OF + Natures Living Soil autoflower concentrate
Nutes: FOOP Veg 1&2 15ml/gal + Sweetener 10ml/gal + FOOP Mist
Light: MH FCE4800 18" @ 75% 20/4
Temp: 72-79°
Humidity: 65-72%
Water: Rainwater + RO @ 23ppm, solution Ph'd to 6.2

Started noticing this rusty discoloration on the oldest triple leaves about 3 days ago and is now becoming more pronounced and spreading. Let me know what yall think. Thanks!

 

[tronN00dles]

What’s the ppm/EC of your nutrient solution?

 

[Hog_M@Gundy]

What’s the ppm/EC of your nutrient solution?

Solution was 245ppm

 

[tronN00dles]

How confident are you in the pH being 6.2? And is this after adding nutes? What kind of meter are you using and is it calibrated?

Either way, my guess is calcium malabsorption due to low pH. Try bringing every thing you pour into the pot, nutes or none, up to 6.5. The leaves are looking a little thicc too, maybe some watering/environmental thing, but that might be separate from the rusting. Looks closer to a calcium issue but between your nutes and soil, I wouldn’t add more. That leads me to think it’s a pH thing….

just my 2 cents…

 

[Hog_M@Gundy]

I was kind of thinking the same thing.. I use a blue lab ph meter, just calibrated it. I adjust the ph after adding the nutes. Maybe I'm not mixing the ph up and down properly and the levels are fluctuating. Im not seeing the rust color at all in my two Mephistos in the same medium. Im going to assume its a ph issue and monitor that more closely.

 

[Hog_M@Gundy]

 

[Hog_M@Gundy]

How confident are you in the pH being 6.2? And is this after adding nutes? What kind of meter are you using and is it calibrated?

Either way, my guess is calcium malabsorption due to low pH. Try bringing every thing you pour into the pot, nutes or none, up to 6.5. The leaves are looking a little thicc too, maybe some watering/environmental thing, but that might be separate from the rusting. Looks closer to a calcium issue but between your nutes and soil, I wouldn’t add more. That leads me to think it’s a pH thing….

just my 2 cents…

I think it was a ph issue from two feeds ago.. Realized that I had mixed my solution a couple hours before using and didnt check the ph again. With the sweetner it probably caused the ph to drop before i used it.. It seems to be resolved now, nothing showing up on any new growth in the past 5 days.

 

[Hog_M@Gundy]

Well, opened the tent tonight and found a bunch of leaves doing the claw and a little more burn showing up on the Muchacha. Is this N Toxicity or something else?
They were fed two days ago a solution @ 445ppm and 6.4ph

 

[Tom Bombadil]

NLS is a water only mix. Water and maybe some molasses... Soil looks too dry as well. Best to keep it evenly hydrated at all times. I would stop feeding for now.. maybe consider it if you see deficiencies in early flower... NLS poops out with bigger strains sometimes...
GL
PS
Not a fan of NLS. Its not aged and the mix can be hot.

 

[Hog_M@Gundy]

Thanks. Yeah, im not a big fan of NLS, looking at something different for next time. FOOP is designed specifically for use with organic living soil. I emailed back and forth with their founder and a rep of theirs before deciding to use it. I had read a lot of people say NLS needed additional nutes once plants hit flower, which prompted me to look into organic nute lines. Definitely gonna lay off feeding for awhile.
About watering I know there are always different opinions, but I was of the understanding that you want the soil to dry a bit between waterings. I first thought it needed to be consistently hydrated, but was told I was overwatering. Maybe I went too far the other direction.

I did give them all a good watering with RO water ph'd to 6.3 last night and they are looking better today.