Brown spots on fan leaves

[cptgold]

Hi,

Would really appreciate some advice on how to stop the cause of these brown spots. Pictures below!

I'm on my second growth now, after upgrading the light I'm stunned by the growth of these girls.
But yesterday night I noticed brown spots on two fan leaves on my White Widow Automatic, pictured in the closeups. The picture of the full plant is from today.
I moved my two plants, the other one is a Royal Jack Automatic btw, to bigger pots 3 days before I noticed the brown spots.
Using the soil from same bag as they were previously in, however, this one got about 15% old dry soil from another bag closest to the leca's in the bottom, as I noticed I didn't have enough. I watered it a bit first to rehydrate it.

Plant
White Widow Automatic Seed
3 weeks old
10 cm (4") tall

Soil
Ecologic soil for herbal plants, enriched with chicken manure, peat, clay, lime, silicon, iron, magnesium, calcium.
Leca in bottom for drainage and oxygen, plus a handful spread into the soil.
10 Liter pots (2.2 gallons)

Light 24/7 (Both plants are Autos)
1x Mars-Hydro TS 1000 LED 150W Compares to: HPS/MH/HID:250W
60 cm (24") hanging distance from top of plant.
Two white walls, two of natural wood.

Ventilation
1x 107 m³/h exhaust fan, grow room is 0.63 m³
1x Oscilating table fan, at intake, giving the plants a fresh breeze

Climate
25-27 °C (77-80 °F) 35-45 RH% (I'm struggling to increase the humidity)

Water
Tap water, no added nutrients, no flushing, let top 3-4 cm (1-2") of the soil dry before watering

I'm planning to improve their environment with a growing tent, for better light reflection and easier climate control. But pretty limited by insane shipping fees to Sweden and a small 61x61 cm (24") closet.

 

[Lesso]

That looks like youre splashing your bottom leaves when you water. Chlorine in the tap water.

 

[Locked]

I never worry about the shape of the bottom leaves. They always get beat up. I only worry about the overall plant health and specifically new growth.

 

[cptgold]

That looks like youre splashing your bottom leaves when you water. Chlorine in the tap water.

We have a very low chlorine tap water here, but possibly burns from the light magnified in the droplets. I'll make sure to be more carefull and not leaving water on the foilage.

I never worry about the shape of the bottom leaves. They always get beat up. I only worry about the overall plant health and specifically new growth.

Seems the plant is fine overall, it still grows rapidly and new growth looks great!


Thanks for the response guys!

 

[rubrown]

Cal/mag is off, first look, second look, yeah your water should set out for 24 hours, don't use RO water

 

[stinkyattic]

Soil mix is a bit "hot" for plants that age, and the pot is oversized for the life stage.
That being said, the plants look overall healthy and are coming into a life stage where their needs better match the soil. No reason to be concerned, keep doing what you're doing. They will tell you when they get hungry.
I'm not familiar with that soil mix but I would personally never use clay indoors, nor chicken manure unless it's pretty old and well composted. However your plants seem to enjoy it ; )

 

[cptgold]

Cal/mag is off, first look, second look, yeah your water should set out for 24 hours, don't use RO water

I've made sure not to splash any water on the plants, however the plant is still getting bad leaves. The worst leaves are bone dry and crumble on touch. However the plant is still growing pretty well, so I'm puzzled. I will try get my hands on some cal/mag and give that a go.
This is after two weeks of no splashing, gentle care and an upgraded setup.

Soil mix is a bit "hot" for plants that age, and the pot is oversized for the life stage.
That being said, the plants look overall healthy and are coming into a life stage where their needs better match the soil. No reason to be concerned, keep doing what you're doing. They will tell you when they get hungry.
I'm not familiar with that soil mix but I would personally never use clay indoors, nor chicken manure unless it's pretty old and well composted. However your plants seem to enjoy it ; )

I started with too small pots, so they were a bit small for their age, once in the more roomy pot they took of quickly, pictured above. But the brown leaves keep appearing. The clay supposedly stabilizes the soil, but I dunno, it was ecologic, specialized for herbs and contained a bunch of nutrients beneficial to this herb

Here's a closeup on some leaves, the bottom one with a visible crack from completely drying up.
The growing light messes a bit with the colors, but it really looks like there's rust on the leaves. No iron taste to the water at all.

Should I remove them btw, all bad ones or just the really dead ones?

 

[oldfogey8]

My gut says that soil isn’t good for your plants. Maybe all the amendments are screwing with the pH. They look hungry. Do you allow the soil to go through a wet/dry cycle?

 

[stinkyattic]

The calmag is a good start. What's your current runoff ph?
Also id angle that fan to not blow right on the plants that close. Or put it up on a chair or something. The plant not directly in front of the fan looks better so there's a variable to consider. I wall mount my fans about 3 feet from the nearest fan to avoid having to worry about this.

 

[stinkyattic]

I should add that with clay soils it's hard to judge if you're overwatering due to both the weight of the medium and the weird way it hangs on to moisture. It's kind of a can of worms to diagnose, since you have a complicated soil mix. At least you're getting new growth so you still have time to turn things around.

 

[rubrown]

I'd cut all those dead leaves off at the stalk, anything brown, 5 mills of cal/mag to a gallon of tap water that's been set out for over 24 hours, maybe top dress with worm casings. Let her dry and hope for the best.

 

[cptgold]

My gut says that soil isn’t good for your plants. Maybe all the amendments are screwing with the pH. They look hungry. Do you allow the soil to go through a wet/dry cycle?

My watering strategy is pretty much stick my finger down, at least to the second joint, if it's dry all the way, water it until right before there's any runoff. Repeat. The time between watering is about 1.5-2 days, the lower end if I use the fan a lot. I go just bellow runoff to keep the nutrients in the soil, as I wasn't adding any nutrients, until cal/mag now. I cross checked all listed nutrients before I bought it, against what cannabis were supposed to thrive off – from 20 minutes of googling with probably a few self-proclaimed "expert" sources though– but yeah I missed the clay, didn't think of that when I got it.
I've got a ph meter now, so I'm planning to test it like every other watering.

The calmag is a good start. What's your current runoff ph?
Also id angle that fan to not blow right on the plants that close. Or put it up on a chair or something. The plant not directly in front of the fan looks better so there's a variable to consider. I wall mount my fans about 3 feet from the nearest fan to avoid having to worry about this.

Took some time to get a ph meter that would measure granular enough to my liking, failed to save the measurements and know only remember once decimal ‍
The water, set for 24h, measured just shy of ph 7.1
runoff from the plant with brown leaves slightly over ph 6.2
and runoff from the other plant ph 6.5

I've moved the fan outside the tent now, keeping a corner of the door opened. Planning to order clip-on fans for easy placement in the tent.

I should add that with clay soils it's hard to judge if you're overwatering due to both the weight of the medium and the weird way it hangs on to moisture. It's kind of a can of worms to diagnose, since you have a complicated soil mix. At least you're getting new growth so you still have time to turn things around.

Yeah, I noticed the weight is unusually hard to go by.

I'd cut all those dead leaves off at the stalk, anything brown, 5 mills of cal/mag to a gallon of tap water that's been set out for over 24 hours, maybe top dress with worm casings. Let her dry and hope for the best.

I cut all the dead leaves and gave them the cal/mag mix three times now. In the first few days I didn't notice any new brown leaves, but today there was a few more of them
Just gave them cal/mag and going to cut the bad ones off again. And I should give worm casings a shot too.

 

[rubrown]

Thanks for posting, yeah I would just let everything dry out till the container is light, about 4 days or so, after that if it didn't improve I would just dump it and start over with new or clean everything. Buying your own dirt, like Roots organic, making sure your tap water has been set out for 24 hrs, being mindful of the wet/dry cycle, using liquid organic nutes like Canna, making sure you use cal/mag, only using nutes after 30 days in new soil all combine to give good flowers. Fertilize every other watering. these things add up for good produce. So please keep us posted. Looks like a nice strain.

 

[stinkyattic]

If your water goes in at 7.1 and comes out at 6.2 you have a serious soil souring issue.
I'm with @oldfogey8 and @rubrown that your soil mix is too complex to troubleshoot once things go pear-shaped, and a bagged mix paired with standard fertilizers will relieve those headaches! I love canna fertilizers but you will definitely want to check the pH of the mixed solution as they can be a bit low. I suspect they have to be packaged that way to reduce spoilage during storage. They have a lot of organic material in them and stink so good! Like the dumpster outside a Vietnamese seafood restaurant on a hot day in july. Mmmm fermented seaweed and fishy goodness. But my plants enjoy them lol.

 

[cptgold]

Thanks for posting, yeah I would just let everything dry out till the container is light, about 4 days or so, after that if it didn't improve I would just dump it and start over with new or clean everything. Buying your own dirt, like Roots organic, making sure your tap water has been set out for 24 hrs, being mindful of the wet/dry cycle, using liquid organic nutes like Canna, making sure you use cal/mag, only using nutes after 30 days in new soil all combine to give good flowers. Fertilize every other watering. these things add up for good produce. So please keep us posted. Looks like a nice strain.

Thanks for the support!
The problem with all these brands I get recommended, none of them are available where I live. When I find some that ships to Sweden, the shipping fees are several times more than the product value I try to figure what actually makes a good soil, so that I can find a good quality north European brand with the same properties.
I think I have a good chance to get a decent yield out of it, planning to start tomatoes and chili's in the tent when these are done. I'm just gardening for my own consumption, so no need to push a super growth instantly. But I really hope to improve for every time, giving me more in between time for other projects and of course better quality buds
I've been making sure to let the water set out 24 hours but mostly more now, separate watering can and always refill it for the next time right after using it.
I think I over watered them when first time after I put them in the bigger pots, as their roots wasn't spread yet the soil stayed wet for almost a week. Didn't water them again until they were proper dried up.
Updated pictures from today below

If your water goes in at 7.1 and comes out at 6.2 you have a serious soil souring issue.
I'm with @oldfogey8 and @rubrown that your soil mix is too complex to troubleshoot once things go pear-shaped, and a bagged mix paired with standard fertilizers will relieve those headaches! I love canna fertilizers but you will definitely want to check the pH of the mixed solution as they can be a bit low. I suspect they have to be packaged that way to reduce spoilage during storage. They have a lot of organic material in them and stink so good! Like the dumpster outside a Vietnamese seafood restaurant on a hot day in july. Mmmm fermented seaweed and fishy goodness. But my plants enjoy them lol.

Sounds like we're onto something, found some symptoms googling. The sour soil dissolves aluminum, manganese etc. inhibiting the growth of smaller roots, increase in height and lots of other bad stuff. Manganese poisoning leads to dried leaves curling up, looking similar to mine.
Do you recommend any specific nutrients and ingredients? The brands are completely different in northern Europe and the few who ships internationally comes with shipping fees multiple times the product price. We don't have Amazon in Sweden yet
The Vietnamese seafood made me lol, I'm thinking about going all organic with seaweed and stuff, but I need a proper air filter first


Just took a few pictures today as this turned into some sort of grow log already
They're now flowering


The plants before pruning. The Royal Jack have had some yellowing of the lower leaves, going to white on some. But both


Using the tent as a photo booth, Royal Jack up first. It's an auto flowering version of Royal Jack. I named her Elsa, looked like a perfect snowflake in those days


The troubled girl, showing of a pretty good deal of buds after all! Named her Consuela, saw a hilarious Family Guy episode stoned and needed a name.


Together back in the tent, until next time!

 

[rubrown]

Those are real nice! I think you did a great job. The basic fertilizers will work fine if you can't find specialized. Those plants are well fed.