Lots of leaves falling, can't figure out cause

Hi everyone,

First some data:

- RH: 40~60
- Temp: 24~27
- PH (runoff): ~6.00
- Strain: Super Lemonade Haze Auto
- Medium: Coco
- Pot size: 5Gal
- Age: 8 weeks
- Nutrients: Plagron Coco A/B + CalMag supplement + Plagron Green Sensation (3/4 recommended dosage)
- Lights: HLG 135W Quantum Board
- Water schedule: 1 day feed - 1 day water => fwfwfw...

Recently (about one week ago or so) I've noticed that almost every leave that stays in the dark parts of the plants (bottom or where light doesn't fully reach) yellows and ends up falling up by themselves or with a light tug up to the point that currently I'm almost picking more than 10 leaves per day. I assumed at first it could've been a nitrogen deficiency so I upped the dosage a bit to 3/4 the recommended dosage (at first, I was giving 1/2) but still nothing has changed.

Also, I've noticed, new grow on those shaded areas, also wilt and dries out. Apart from all of this, they started going really well but I've noticed that bud development is slowing down a lot and barely have any bud growth.

However, when you look at the plant from above, it looks healthy without any leaves showing any problems. So I'm running out of ideas of what to try.

Anyone has any pointers as to what it can be? Thanks a lot.

Fallen leaves:


New growth dying:


Leaves in the dark yellow and dry out


Slow bud development (been like that for a week, and it's supposed to be on week 8 of 11 according to the breeder)


Plant from above looks healthy:

looks like nute burn what is your ec?

Thanks for your reply. Here's a sample of the mix I used to feed them today (base water ec is around 680~):

that is way too high at that stage you should not be over 1400-1500.

If your base water is 650 yous should get some reverse osmosis going

Just by glancing at it.. i would suspect you may be running into the start of a root issue.

steve870 said:

that is way too high at that stage you should not be over 1400-1500.

If your base water is 650 yous should get some reverse osmosis going

Click to expand...

Thanks, I was following this schedule but with reduced quantities:

yes but your water is already at 680

Merkn4aSquirtn said:

Just by glancing at it.. i would suspect you may be running into the start of a root issue.

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What kind of issue do you think it might be? I also thought about it but usually, every time I pick them up before watering, the pot feels really light so I assumed there's barely any water left and I also always read that root rot with coco is nearly impossible. So I have no idea what can it be.

steve870 said:

yes but your water is already at 680

Click to expand...

I'm really not familiar with RO at all, can you point me to a place where I can learn a bit more on how to do it, etc ?

Hmm what size pots, how often do you feed, do you get runoff each time you water? Have you checked the runoffs ec to see if there's a possibility of a salt build up?

Merkn4aSquirtn said:

Hmm what size pots, how often do you feed, do you get runoff each time you water? Have you checked the runoffs ec to see if there's a possibility of a salt build up?

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5Gal fabric pots. I feed every other day. I do get around 10%~15% of runoff water. I haven't checked ec of runoff only PH, will do it next time.

growlars said:

I'm really not familiar with RO at all, can you point me to a place where I can learn a bit more on how to do it, etc ?

Click to expand...

Or maybe should I use bottled water?

reverse osmosis is a membrane that's separate minerals and salts from water it's a bit like a filter

just start by lowering your ec to less than 1000 and flush them a bit with that and check runoff ec

if they dry out quickly it's a good thing for you because you can flush them without overwatering them

steve870 said:

just start by lowering your ec to less than 1000 and flush them a bit with that and check runoff ec

if they dry out quickly it's a good thing for you because you can flush them without overwatering them

Click to expand...

But should I lower the EC adding less nutrients or using something like bottled water which will probably have a lower base EC?

Im running coco in 5 gal pots too. I water every 36 hours. When i feed them i give them 1 gal of usual nutes.. usually i get no runoff. 10 mins later i feed a half gallon at 50% nute. I'll get most of that runoff back.. when i check ph its exactly what i put in minus 200 or 300 ec.(im feeding 1200ppms) so ppm is usually around mid or high 900's

Merkn4aSquirtn said:

Im running coco in 5 gal pots too. I water every 36 hours. When i feed them i give them 1 gal of usual nutes.. usually i get no runoff. 10 mins later i feed a half gallon at 50% nute. I'll get most of that runoff back.. when i check ph its exactly what i put in minus 200 or 300 ec.(im feeding 1200ppms) so ppm is usually around mid or high 900's

Click to expand...

Thanks, I'm gonna try to leave them without watering for longer to see how they react as well.