Clawing and low ec issues

lockedshed · Apr 1, 2026

Hi, my plants have leaves that curl down, especially near the tips.
4 x feminized photos.
No tip burn, pictures show light near tips but they are the same green all the way.
Plants about 5/6 weeks old

feed with:
1ml/litre cal mag
2ml/litre canna A+B, 1.5 litres once a day, with 800ml runoff. (Upped to 2.5ml/litre A+B as run off ec was low)
Two of them have algae on the top (one is the worst clawing)

Example from two plants:

Purple punch 2.0 (most clawing)
Ph in - 5.83
Ec in - 1.7
Ph out - 6.0
Ec out - 1.3

Green crack 2.0 (healthiest and biggest plant)
Ph in - 5.89
Ec in - 1.9
Ph out - 6.31
Ec out - 1.1

Substrate - Canna coco premium pre buffered 70%, perlite 30%.
Ph tap water

18/6 light.

Lights on temp: 23-24c
Lights out temp: 19-21c

RH: 65%ish

Vpd - 0.8 - 1.0

Calibrated apera ph60 pen
Calibrated blue labs ec pen

Ac infinity 4x4 tent
Ac infinity 6 inch inline fan (setting 1 - 3)
2 ac infinity oscillating fans on settings 2 and 4, not pointed at plants.
Mars hydro Fce6500 light, 370 ppfd (34-ish DLI I think) - ive turned this down to 320ppfd.

Is the lower ec out a problem and am i under feeding?

am i over watering getting 50% run off daily?

Is my light the issue?

Grownsince95 · Apr 1, 2026

Cut your calmag dose in half and replace the "missing" EC with your a & b. Calmag is an EC hog and takes up too much space. Or you can add the .6 EC you're dropping back with more a & b and leave the calmag the same. What's the EC of your tap water?

5O% runoff is a bit wasteful of your food supply but it's not hurting.

See how they respond before you adjust the light anymore.

lockedshed · Apr 1, 2026

Grownsince95 said:
Cut your calmag dose in half and replace the "missing" EC with your a & b. Calmag is an EC hog and takes up too much space. Or you can add the .6 EC you're dropping back with more a & b and leave the calmag the same. What's the EC of your tap water?

5O% runoff is a bit wasteful of your food supply but it's not hurting.

See how they respond before you adjust the light anymore.

Tap water is 0.1

Can you explain the bit you said about the 0.6 EC you're dropping back.
Do I add more a + b to replace the cal mag and make the same EC - 1.9 (instead of 1ml cal mag and 2.5ml A + B, I do something like 0.5ml cal mag and 3.0ml A + B?)

Is the cal mag causing the clawing and is my watering once a day ok? (I'll cut back a bit from 1.5 litre to get less run off)

Thanks btw

WinJr63 · Apr 1, 2026

My friend, ur best bet is to goolge ur plants problems, it could be a few b4 people chime in.

I see white tips on some leaves, I would bet nitrogen toxicity.

lockedshed · Apr 1, 2026

WinJr63 said:
My friend, ur best bet is to goolge ur plants problems, it could be a few b4 people chime in.

I see white tips on some leaves, I would bet nitrogen toxicity.

Hi, I said in my original post that the tips look white because of the light.
They are the same green as the rest of the leaf.
I can take a picture of them uncurled and at a different angle.

Being that the tips are green, what do you think the issue is?

I think what you posted was ai from Google which is often wrong on a range of subjects so I wouldn't trust that.

I thought experienced growers help on a dedicated site, with a section to help people with plant issues was a bit better than Google ai - am I wrong?

trygrowup · Apr 1, 2026

lockedshed said:
I thought experienced growers help on a dedicated site, with a section to help people with plant issues was a bit better than Google ai - am I wrong?

Well in a way google is kinda right i think. In the way that it suggest some possibilities. That could help exclude some things.
As i was told, clawing is a sign of stress, so thats why there is not one answer.
But i totally get what you're saying but it will be a little the same with our answers.
You will be the best to judge what answer or reason could fit your situation

I will say in my ears 50% runoff every day sounds like a lot too, but maybe for your medium it's ok.

Jmaes Mabley · Apr 1, 2026

Your irrigation pattern is the smoking gun

You’re giving:
1.5 L in
800 mL runoff
That’s 53% runoff every single day.

In coco, that means:

the medium never re‑oxygenates
the top never dries
algae forms
roots suffocate
leaves claw downward

This is textbook root hypoxia.

Coco is hydroponics — hydroponics needs oxygen, not constant saturation.

lockedshed · Apr 1, 2026

trygrowup said:
Well in a way google is kinda right i think. In the way that it suggest some possibilities. That could help exclude some things.
As i was told, clawing is a sign of stress, so thats why there is not one answer.
But i totally get what you're saying but it will be a little the same with our answers.
You will be the best to judge what answer or reason could fit your situation

I will say in my ears 50% runoff every day sounds like a lot too, but maybe for your medium it's ok.

Thanks.
Google is suggesting its over watering, from what the guy posted.
Im in coco and im getting told that over watering is impossible.
For plants my size in a 5 gallon pot, 1.5 litres once daily doesn't sound much from my research, though 50% run off is higher than the 10 - 30% I see.
I'll water 1 litre with stronger nutes and cut the cal mag back by half, and maybe cut my light back more.

lockedshed · Apr 1, 2026

Jmaes Mabley said:
Your irrigation pattern is the smoking gun
You’re giving:
1.5 L in
800 mL runoff
That’s 53% runoff every single day.

In coco, that means:

the medium never re‑oxygenates

the top never dries

algae forms

roots suffocate

leaves claw downward

This is textbook root hypoxia.

Coco is hydroponics — hydroponics needs oxygen, not constant saturation.

Thanks, I'll look into it. What would you suggest I do to remedy this?

Ive read and been told i cannot over water in coco.
When I water once daily, I'm introducing oxygen to the roots.
Coco should be saturated at all times...etc..etc

There is so much conflicting information from everywhere.
im on here, reddit, Facebook, im looking at other sites and Google.
Everything is conflicting.
Cocoforcannabis says I should be watering twice or more daily at this point.
I dont know what the hell to do

WinJr63 · Apr 1, 2026

lockedshed said:
Hi, I said in my original post that the tips look white because of the light.
They are the same green as the rest of the leaf.
I can take a picture of them uncurled and at a different angle.

Being that the tips are green, what do you think the issue is?

I think what you posted was ai from Google which is often wrong on a range of subjects so I wouldn't trust that.

I thought experienced growers help on a dedicated site, with a section to help people with plant issues was a bit better than Google ai - am I wrong?

Sorry missed that, u said light not white.

Many problems can be ruled out.

If not already I would put lights at about 20" from top of canopy as plants get taller move lights up and adjust ppfd.

As for watering/feeding what NPK ratio are u feeding? plus what size pots ?

Edit, u just post 5 gallon pots

lockedshed · Apr 1, 2026

WinJr63 said:
Sorry missed that, u said light not white.

Many problems can be ruled out.

If not already I would put lights at about 20" from top of canopy as plants get taller move lights up and adjust ppfd.

As for watering/feeding what NPK ratio are u feeding? plus what size pots ?

Edit, u just post 5 gallon pots

Npk ratio....?
Im using canna coco a A + B, just gone from 2.0ml/litre to 2.5ml/litre.
I also use 1.0ml/litre cal mag.

WinJr63 · Apr 1, 2026

lockedshed said:
Thanks, I'll look into it. What would you suggest I do to remedy this?

Ive read and been told i cannot over water in coco.
When I water once daily, I'm introducing oxygen to the roots.
Coco should be saturated at all times...etc..etc

There is so much conflicting information from everywhere.
im on here, reddit, Facebook, im looking at other sites and Google.
Everything is conflicting.
Cocoforcannabis says I should be watering twice or more daily at this point.
I dont know what the hell to do

Many growers do a dry back not totally dry u lift pot for heaviness stick fingers in soil for dryness, there is lots of info for this u will learn it ur coco coir can be water soggy if watering every day with 50% runoff.

Gotta run

lockedshed · Apr 1, 2026

WinJr63 said:
Many growers do a dry back not totally dry u lift pot for heaviness stick fingers in soil for dryness, there is lots of info for this u will learn it ur coco coir can be water soggy if watering every day with 50% runoff.

Gotta run

Yeah so much conflicting information.
I will learn thanks, hopefully sooner rather than later

WinJr63 · Apr 1, 2026

What week are ur plants? The last time u water/feed ?

JIMKSI64 · Apr 1, 2026

You are doing well not listening to the soil guys telling you to dry out coco.

I do not do hydro coco but am surprised that no one has said you just need to fertigate more often with less runoff.
Once a day is normally not taking advantages of the hydro growth and some folks here will do 4 ferts a day.
Look into this or perhaps a coco grower can chime in for confirmation and how to balance your numbers.

lockedshed · Apr 1, 2026

WinJr63 said:
What week are ur plants? The last time u water/feed ?

Week 5/6 I believe.
I fed 1 litre 5 hours ago, 1ml/litre cal mag 2.5ml/litre canna A + B, With 300ml run off

lockedshed · Apr 1, 2026

WinJr63 said:
Many growers do a dry back not totally dry u lift pot for heaviness stick fingers in soil for dryness, there is lots of info for this u will learn it ur coco coir can be water soggy if watering every day with 50% runoff.

Gotta run

Im in coco not soil. Is this not different?

WinJr63 · Apr 1, 2026

Ok thats like 30% runoff per plant, lift the pots to get a feel for the weight of each plant pot.

Next day Stick fingers in soil 2-3 inches if its still wet don't feed, if its dry feed, lift pot for weight feel.

Once the plants get bigger you'll go by finger feel or a use a stick or soil moisture meter.

NPK is on ur fert bottles 4-0-1, 1-4-2

ur plants are droopy overwatered .

Jmaes Mabley · Apr 2, 2026

Also, I myself, like temps more in the range of 27.8c-28c. Plants will use water/food faster, and less chance of overwatering as evaporation, and transpiration rates will be faster. Also get all the fresh air exchange you can. No such thing as to much fresh air exchange.

WinJr63 · Apr 2, 2026

Jmaes Mabley said:
Also, I myself, like temps more in the range of 27.8c-28c. Plants will use water/food faster, and less chance of overwatering as evaporation, and transpiration rates will be faster. Also get all the fresh air exchange you can. No such thing as to much fresh air exchange.

Very true im hitting around 80f now, might half to water/ feed every other day in 0.5 gallon pots.

Clawing and low ec issues

Clawing and low ec issues

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Clawing and low ec issues

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Your irrigation pattern is the smoking gun

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