Brown spots spreading

[OldGrumpy]

Problem:
Brown spots on leaves (Both lower and upper)

Medium/grow method:
80% garden soil, 10% perlite, 10% diluted cow manure
Composition of garden soil
NPK 14-7-15 mkro 1,5 kg
mg/l
(N): 240
(F): 70
(K): 250
(Mg): 200
(Ca): 350
(S): 120
(B): 0,5
(Cu): 1,7
(Fe): 70
(Mn): 20
(Mo): 0,7
(Zn): 4,0

Feed: and supplements used:
Gold Label Special mix. Started introducing nutrients late and gradually. First feed was week 4 (on veg schedule) and 2 days ago (week 7) was the first feed close to 100% of the recommended strength and the first feed on the flowering schedule (http://www.goldlabel.nl/7/Nutrient-Schedules.aspx)

water source:
pH-adjusted tap water. I water when the soil is almost completely dried out.

Strain/age:
Autos / 7 weeks

light used:
UFO-120 CreeLeds Osram led grow light (on veg mode for the first four weeks, on veg+flower since then) 18/6 light/dark.

Climate:
During veg, 75% rH, 18°C , 2 weeks into to flowering changed to 23°C and rH 50%

Additional info:
Plants are looking well except for these discolourations I noticed the other day and they are spreading. The attached pictures are from two days ago and the problem has gotten slightly worse since. Any help on diagnosing this would be hugely appreciated. I have my suspicions as to what the problem may be, but I'd like some advice before i begin to tinker.

 

[dickfitzwell]

is this what you are seeing?

Phosphorus: P; (mobile; absorbed as H2PO4-, HPO4--) ....usually larger patches of necrosis, internal, margins,... sometimes can look a lot like Ca defc.

View attachment 543839

>>>less common, weirder symptoms:

**** a truly weird manifestation here, not 100% sure it's P defc, but it fits the criteria well enough,... can't account for the colors, so trippy! -->

>>> Cool temp's can slow P uptake down, and can cause the classic purpling effect; seems to be unique to this specific situation... (of course, some strains are purple or turn purple as part of normal genetic expression regardless of temp's)...

 

[Arthur]

Looks to be calcium deficiency, phosphorus can also kinda be evasive, looking like other things for a bit. I'd get a soil pH, and see where that sits, at that point you'll have more of a direction to head. A low soil pH could cause issues with uptake of both.

p

 

[OldGrumpy]

is this what you are seeing?

That resembles it

Looks to be calcium deficiency, phosphorus can also kinda be evasive, looking like other things for a bit. I'd get a soil pH, and see where that sits, at that point you'll have more of a direction to head. A low soil pH could cause issues with uptake of both.View attachment 1090768p

I added some cal-mag nutrients today to rule that out. pH readings are 6.4-6.6

I might have found the issue, when adding nutrients ive always batched them in the same water. Found this on the information about the nutrient pack, "Never combine pure nutrients together, always mix in water." That means they all need to go in separate watering, huh?

 

[Arthur]

That resembles it



I added some cal-mag nutrients today to rule that out. pH readings are 6.4-6.6

I might have found the issue, when adding nutrients ive always batched them in the same water. Found this on the information about the nutrient pack, "Never combine pure nutrients together, always mix in water." That means they all need to go in separate watering, huh?

Sounds like that could be the issue. I can have similar problems if I mix my line out of order.

 

[Arthur]

I'll add to that... never mix usually means together BEFORE watering. I would think if you add A and mix thoroughly, then B and mix... and there may be an order they want you to add.

If I screw up the line I run, I can literally watch the nutrients fall out of suspension.

 

[dickfitzwell]

Just shake it between each thing you add so you don't get nuits lock out

 

[OldGrumpy]

is this what you are seeing?

Looks like you were right, most likely phosphorus deficiancy.
Adding Cal-mag did nothing and the problem has gotten worse since my last post. Gave a full feed of veg+bloom nutes. Hopefully that will save the day.

I have 6 plants all on the same nutrient schedule and only this plant is having difficulties, weird!

 

[dickfitzwell]

some plants can be whore's about some nuits i hope you get you shit right. It sucks when your shit ain't perfect, i know that feeling all to well. im to a point i give my plants the whole line up of foxfarm.

 

[OldGrumpy]

some plants can be whore's about some nuits i hope you get you shit right. It sucks when your shit ain't perfect, i know that feeling all to well. im to a point i give my plants the whole line up of foxfarm.

Im a novice, first grow and all. From my research i gathered that autos didnt need much additional nutrition and there was a big risk of nutrition-burn. Potting soil + manure was supposedly enough. Ill need to revise my list of trusted sources!