Problem in coco coir

shortarker99

shortarker99

Well-Known Member
Hi

Most of them are looking like these.

R/O Water Ec 1.8 pH 5.8. Water temp 18/21 Celcius.

Ambient temp 24C. 65-70% humidity

Any opinion? I tried many different watering strategies, no improvement. They are drinking but can't make symptoms go away. I suspect FeEddha is expired (bought it in 2022). I prep the nutrients by myself, never a problem
1722032104284.jpeg
 
shortarker99

shortarker99

Well-Known Member
Hi guys.
Sorry for the long delay. Im still battling with this. I suspect this is Mg deficiency
pH is at 6.

I tried these without success
  • Fungicides
  • Chlorine at nutrient solution at 400mv ORP
  • Trichodherma
  • Different ECs
  • Osmosis Water
  • Different source water
  • Desinfect whole water system
Last thing was re-buffering coco coir with calcium nitrate as said here https://scienceinhydroponics.com/2017/04/using-coco-coir-in-hydroponics.html

ec121 said:
Have you measured your runoff EC? How often are you feeding each day? What is the PPFD? Is that coco and what else in the media?
Click to expand...
There are some plants that im feeding 1x a day, and others they take many days to drink the water.
PPFD is around 600. Coco Coir

This was i plant i rebuffered its coco 8 days ago
1731955516244.jpeg

Today.. looks worse IMO

1731954537032.jpeg

In a greenhouse i have outside the same plant gets better with same nurtrients.I read that with more light, more Mg is required, can be the case? (More light indoor vs greenhouse)

SouthFloridaGenetics said:
I think they need more food. I would put the pH=6.2 or so if it were my responsibility as well.
Click to expand...
These months i always stayed in the 5.8-6.2 range, don't think it makes any difference tbh


----

This is a plant i transplanted few days ago. You can see it starts showing some intervenal chlorosis as older plants

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Last edited:
Wastei

Wastei

Well-Known Member
When you say prep your nutrient? What's in that mix? Mineral salts don't really go bad if stored properly.

If you made the mix by yourselfs it's probably down to that mix but that's just guesswork without any data.

"Never experience any problems" doesn't help much at troubleshooting. Mineral ratios are probably off. What other changes have you been doing? Different light source?

pH 5.8-6.2 is to low for growing in soilless IMO. Algae growth will worsen aeration and plants access to oxygen. I use a light dose of oxidizer to keep it away.

Cheers!
 
shortarker99

shortarker99

Well-Known Member
Wastei said:
When you say prep your nutrient? What's in that mix? Mineral salts don't really go bad if stored properly.

If you made the mix by yourselfs it's probably down to that mix but that's just guesswork without any data.

"Never experience any problems" doesn't help much at troubleshooting. Mineral ratios are probably off. What other changes have you been doing? Different light source?

pH 5.8-6.2 is to low for growing in soilless IMO. Algae growth will worsen aeration and plants access to oxygen. I use a light dose of oxidizer to keep it away.

Cheers!
Click to expand...
Im applying chlorine to reach 400mv ORP as oxidezer. And regarding the expiration. I tried using new salts, no success.

This is the formula
1731955704613.png

These are the salts
1731955745955.png
 

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Wastei

Wastei

Well-Known Member
shortarker99 said:
Im applying chlorine to reach 400mv ORP as oxidezer. And regarding the expiration. I tried using new salts, no success.

This is the formula
View attachment 5440205

These are the salts
View attachment 5440207
Click to expand...
That Calcium to Magnesium ratio is way off and probably why you're experiencing less problems outdoors where it gets diluted.

That's almost a 1:1 ratio where you should aim for 2:1 to 4:1 Ca:Mg ratio growing Cannabis. Fix that and your problems should disappear.

Cheers!
 
shortarker99

shortarker99

Well-Known Member
Wastei said:
That Calcium to Magnesium ratio is way off and probably why you're experiencing less problems outdoors where it gets diluted.

That's almost a 1:1 ratio where you should aim for 2:1 to 4:1 Ca:Mg ratio growing Cannabis. Fix that and your problems should disappear.

Cheers!
Click to expand...
I also grow in coco coir pots outdoors.

Will try with a small batch.. Still i dont see how a higher amount of Mg will result in Mg deficiency, i think i should see a Ca deficiency in that case as Mg is competing with Ca.
 
MickFoster

MickFoster

Well-Known Member
shortarker99 said:
There are some plants that im feeding 1x a day, and others they take many days to drink the water.
PPFD is around 600. Coco Coir
Click to expand...
That's a problem........coco should be fed at least once a day to substantial run off. It should always be fully saturated........you don't wait for the plants to drink the water. Also, even though you didn't mention it...........never give plain water.
 
shortarker99

shortarker99

Well-Known Member
MickFoster said:
That's a problem........coco should be fed at least once a day to substantial run off. It should always be fully saturated........you don't wait for the plants to drink the water. Also, even though you didn't mention it...........never give plain water.
Click to expand...
Kept it fully saturated, same problem. And when did it people told me it was overwaatering lol
 
Last edited:
Poltrack

Poltrack

Member
This
You're using an heptahydrate at (maybe) the dose of a dry (no volume referential in the table).
It's like the thiosulfate, if you're using a pentahydrate you have to dose a bit more to reach the sale molar rate.
 
shortarker99

shortarker99

Well-Known Member
Poltrack said:
This
You're using an heptahydrate at (maybe) the dose of a dry (no volume referential in the table).
It's like the thiosulfate, if you're using a pentahydrate you have to dose a bit more to reach the sale molar rate.
Click to expand...
Good point. However, i would have tu use less if using penta since it has more Mg in it. but still isnt such a difference (8%). I dont think it really matters.
Those quantities are for 750L = 200 gal of solution
 
shortarker99

shortarker99

Well-Known Member
Those 3 marked plants have a special brand of coco which is pre-buffered. The rest and worst ones are made from coco bricks and buffered by me.

1731979336001.png

These 3 are growing faster and stronger, though they also have some deficit signs. Not as strong as the rest

1731979569999.jpeg


And this one is from a greenhouse outside, same genetic & nutes, with coco from bricks
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