What is causing this? Spots on curled down and twisted leaves

Hello everyone! Please, i need help once again!

I'm growing 2x autos (Auto Mandarina and AK48 Auto) in soil.
The light is a SF-1000 (100W led) that's always on at 80-100%
The grow area is a cabinet with very good airflow: 2x internal fixed USB fans - one at max settings, pointed at the light, and the other at minimum settings, pointed at the plants - and 1x extraction PWM fan - the Noctua NF-A14 iPPC-3000 heavy duty PC fan.

I usually water with dechlorinated (48h) tap water - pH is 7.5-8.0 | EC is 1328 µS/cm | ppm is 839 - which is as hard as it gets around here, and understand when the plants need their water thanks to observation and 24/7 timelapses.

Gave Biobizz Root Juice the first week and they loved it.
Gave 1ml/L of Biobizz Biogrow and 1ml/L of Biobizz Bioheaven to the Auto Mandarina a couple of times last week because of very rapid growth.
Everything was looking pretty good.

I then watered with plain tap water just before i was to leave town for 3 days.
Temps were somewhat cool (20-24 °C) and humidity was spot on (60-70 °C) during my trip.
No risk of drying since the soil mix is medium-light for the Mandarina and regular-light for the AK48 Auto. Both mixes are 30% perlite but the Mandarina has some tough rich organic soil in her mix too (various peats + river sand + green composted amendments, originally marketed for vegetable gardens).

When i came back i found the Auto Mandarina - that was perfect the day that i left - extremely curled down, clawing hard and with new growth tips long, skinny, with edges curling inwards and also showing some twisting. Still, no markings on the leaves. Pot was somewhat dry, but still had enough moisture in it for the plant to not look like she looked. Stalk and stems weren't "limpy" and when i looked at the timelapse she curled rapidly in the timespan of 4-6 hours, just the day before i came back, and even then, she kept growing!

The AK48 Auto on the other hand was just a tad bit droopy. Gave to her less water than the sister, and was a tad bit drier than the other (by design and as i expected, since she's 1 week younger than her sister).

I watered normally and tried to wait it out since i wasn't sure what was the cause of the grim looks.

After a couple of days, now markings on the leaves are starting to appear on both the plants and the Mandarina's curling/clawing as well as AK48's drooping - are not going anywhere!

Please help them, for the love of god!

Auto Mandarina today, at Day 23:


AK48 today, at Day 16:

It looks very similar this guy's problem:

Looks like a combination of PH fluctuations and overwatering. Did you give them alot of water before trip?

If you grow in a peat moss medium like promix since it is already acidic, don't lower your ph lower than 6.7 unless you want yellow plants and a runoff of 5.0. Plus thoses who feed your soils.. microbes love a less acidic PH.

Maybe lower your ph a little bit to 6.8 or 7?

Lol I water my plants with a ppm of 500 in the first 3 week so if your tap water is as hard as 800PPM buy a reverse osmosis system and add the cal mag yourself? Maybe flush an overaccumulation of 'Bad' nutes already present in your hard water; wich compete with the real nutes and may kill the microbes in your soil

You will never get any good result straight from this water. Never. If it come out of the tap with a ppm of 800

HiddenFarm said:

Looks like a combination of PH fluctuations and overwatering. Did you give them alot of water before trip?

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Nope, i don't water enough to even make it run off:
- 0.75L to the Auto Mandarina
- 0.33L to the AK48 Auto

Next watering was 4 days later:
- 0.9L to the Auto Mandarina
- 0.5L to the AK48 Auto

Soil seemed drier than usual and slight drooping on the AK48 Auto so i decided more water, but now that i think about it:
- the Auto Mandarina pot could've used less water just by looking at it, so she may have been slightly overwatered after i came back, but the weird thing is she was more curled/clawed before i watered her rather than just after watering her or even now, 1 day after watering her. That doesn't make any sense.
- the AK48 pot could've used a bit more water since it was barely any damper after watering than before, it must've been more on the drier side.

Soils pHs are advertised as 5.8-6.0 (the tougher "garden" one) and 6.5 (the lighter "potting" one) and the mixes are:
- Auto Mandarina is 1/3 tougher, 1/3 lighter and 1/3 perlite (mixed by hand).
- AK48 Auto is 2/3 lighter and 1/3 perlite (no tougher one, also mixed by hand).

So overall i think that the Auto Mandarina could be:
- overwatered (?) and/or not liking the tougher soil
- very slightly N toxic (leaves are slightly dark and shiny, i think i could've overdone it but i don't see any nute burns so idk)
- slightly other-things-deficient (typical P, S, Ca and Bo caused by pH swinging upwards)

The AK48 Auto instead could be:
- slightly underwatered
- more other-things-deficient than her sister since her pot has higher soil pH to being with and the overall pH then swinged upwards even harder, hence the more prominent and evident markings on the leaves but no curling/clawing.

Gift.weed.exe said:

You will never get any good result straight from this water. Never. If it come out of the tap with a ppm of 800

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Look at my grow journal bud, just pulled 85g under 90W with a photoperiod plant, she was eating HELLA nutes on top of already high dissolved solids in the water, and i've been replicating the same exact conditions, except soil (run out of it, had to buy a "newer version" and recycled one i already had) and climate (now cooler and more stable since autumn, not summer).

It could be the water is too hard for autos though, since i can't for the life of me grow these needy fucking bitches

Gift.weed.exe said:

Lol I water my plants with a ppm of 500 in the first 3 week so if your tap water is as hard as 800PPM buy a reverse osmosis system and add the cal mag yourself? Maybe flush an overaccumulation of 'Bad' nutes already present in your hard water; wich compete with the real nutes and may kill the microbes in your soil

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839 is the "Dry residue at 180 °C in mg/L", and i'm not sure about the correct ppm conversion...
Sorry about the misunderstanding, but i don't have EC/TDS meters, i just read my town's water quality analysis report.

ComputerSaysNo said:

It looks very similar this guy's problem:

Quick one autoflower twisting and drooping leaves

Hi, i have problem with my quick one soil grow, Plant started flowering 12 days ago, Leaves are drooping and few have holes/cracks pretty sure not bugs also some leave stems are purpleish. New growth has twisting in the tips. I cant rember when it started maybe few weeks ago, any help, sorru...

rollitup.org

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What's your take?
His plants don't look like mines at all imho.

Entusia said:

I usually water with dechlorinated (48h) tap water - pH is 7.5-8.0

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Just think it's a bit hard water. I usually try to get around PH 6.5 in soil.
Where I live we have 7.2 PH in tap so I have to lower a bit.
I would try to soften the water for a couple of day to see if that help.

HiddenFarm said:

Just think it's a bit hard water. I usually try to get around PH 6.5 in soil.
Where I live we have 7.2 PH in tap so I have to lower a bit.
I would try to soften the water for a couple of day to see if that help.

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Simplified version of what I've just said above, but facts. (tough I wouldn't go any lower than 6.8 since it worked fine with a high PH until now)

Entusia said:

What's your take?

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I honestly don't know. The water is extreme at over 1.3 EC, who knows what's in there? (Should be on the analysis report, though.)
Edit: just saw the screenshot you posted. 161 mg/L for calcium, sodium at 102 mg/L, that's a lot (we have 30 and 15 in our water, for comparison).

7.5-8 is not unusual for tap water (same here, and we lower to around 6.5 for the soil grows, with BioBizz nutes and Light Mix). EC is much lower for our water (around 0.3-0.4...).

But as you said, you already had a successful run with that water, on the other hand it was in different soil.

It's not relevant now, but if I was you I would go with coco next time, maybe switch to mineral fertilizer, possibly use RO water. It's easier to control and watering is easier, too. If you go coco, you definitely will not need a calcium supplement; if you use GHE nutes you'll have to use their hard water micro.

Entusia said:

His plants don't look like mines at all imho.

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In the thread that I linked, there's another picture posted which looks quite similar to yours (brown spots).

ComputerSaysNo said:

Edit: just saw the screenshot you posted. 161 mg/L for calcium, sodium at 102 mg/L, that's a lot (we have 30 and 15 in our water, for comparison).

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Gift.weed.exe said:

Simplified version of what I've just said above, but facts. (tough I wouldn't go any lower than 6.8 since it worked fine with a high PH until now)

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Will try using (glass) bottled water, the one we drink, for a little bit, but definitely not for long cause it's quite expensive and really unpractical.
14 mg/L calcium, 3 mg/L sodium, 85 µS/cm EC, 8.5 pH.

What do you reckon? Maybe add a little CalMag to stabilize it, and after that pH it to 6.5-7.0?

ComputerSaysNo said:

In the thread that I linked, there's another picture posted which looks quite similar to yours (brown spots).

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Didn't see it at first, imho looks way more overwatered and deficient/problems with way higher pH, but i guess that's where my two plants are headed to if i don't steer them back on a sane path.

Entusia said:

Will try using (glass) bottled water, the one we drink, for a little bit, but definitely not for long cause it's quite expensive and really unpractical.
14 mg/L calcium, 3 mg/L sodium, 85 µS/cm EC, 8.5 pH.

What do you reckon? Maybe add a little CalMag to stabilize it, and after that pH it to 6.5-7.0?


Didn't see it at first, imho looks way more overwatered and deficient/problems with way higher pH, but i guess that's where my two plants are headed to if i don't steer them back on a sane path.

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Where I live you can get a gallon of distilled water in any food market for a buck, only need to supplement cal mag since distilled water contain nothing, but you need a healty amount of cal mag in in your water lets say about 200ppm. Or buy a Reverse Osmosis system for 200 bucks

But before buying a RO system I would consider buying a ppm meter to see the real ppm of that water, even the cheapest one on amazon would do.. I'm curious about how hard your water really is

If it's practical at all, use rain water.

Also, as @Gift.weed.exe says, distilled water is not expensive, but in the long run, an RO setup might pay off. Maybe you can just dial it in with tap water; it does have a lot of stuff in it, but it should be possible to make it work.

An RO filter will cost you maybe €200, but you can also use the water from it for other things, like making coffee, tea, drinking water, water for cleaning windows, ...
It's probably worth the money in your situation.

ComputerSaysNo said:

If it's practical at all, use rain water.
[...]
An RO filter will cost you maybe €200, but you can also use the water from it for other things, like making coffee, tea, drinking water, water for cleaning windows, ...
It's probably worth the money in your situation.

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You should sell RO systems

Gift.weed.exe said:

But before buying a RO system I would consider buying a ppm meter to see the real ppm of that water, even the cheapest one on amazon would do.. I'm curious about how hard your water really is

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The quality report is pretty accurate. Those are the analyses of my 3k population "town".

Entusia said:

You should sell RO systems

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RO water is great; but our tap water is so clean that it is practically a waste of money to buy an RO processor.

I have not tested if RO water actually makes tea or coffee taste better, it surely does if the tap water is crap. The point about the window cleaning was not a joke, it is actually used by commercial window cleaners because it leaves hardly any trace when drying off.

Entusia said:

The quality report is pretty accurate. Those are the analyses of my 3k population "town".

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At least they're honest about it .