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  • Struggling with understanding runoff ec.

Struggling with understanding runoff ec.

  • Thread starter Thread starter OutdoorGanja
  • Start date Start date Apr 27, 2026
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Struggling with understanding runoff ec.

OutdoorGanja Apr 27, 2026 4 Replies 545 Views
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OutdoorGanja

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#1
Hey y'all,

I've been trying to follow the cocoforcannabis website advice regarding measuring runoff, and i have consistently been getting lower runoff ec, adding more feed each time to the point where im now feeding it at like 3.0 ec. My plant is around 4 weeks old, yesterday i fed her a solution of 1480ppm, which has almost DOUBLE of the recommended dose of my grow nutrient, and i got a runoff of 1180. And then today i noticed the slightest clawing and a burnt tip.

Im using organic biobizz fish mix, which im guessing might be the issue? is reading runoff ppm not accurate when using organics? Im thinking of just switching to coco specific mineral nutes as i already had a feeling the fish mix isnt doing much in coco. Love to hear what yall think about this
 
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Ninjadogma

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#2
OutdoorGanja said:
Hey y'all,

I've been trying to follow the cocoforcannabis website advice regarding measuring runoff, and i have consistently been getting lower runoff ec, adding more feed each time to the point where im now feeding it at like 3.0 ec. My plant is around 4 weeks old, yesterday i fed her a solution of 1480ppm, which has almost DOUBLE of the recommended dose of my grow nutrient, and i got a runoff of 1180. And then today i noticed the slightest clawing and a burnt tip.

Im using organic biobizz fish mix, which im guessing might be the issue? is reading runoff ppm not accurate when using organics? Im thinking of just switching to coco specific mineral nutes as i already had a feeling the fish mix isnt doing much in coco. Love to hear what yall think about this
Click to expand...

Understanding the strength of those values can go a long way helping you. The highest value those roots should ever experience is 2.8 and that's the peak flower feed around week 6-7. For most of the mature plant's life until it flowers it should be kept under 2.0 and a happy range is about 1.4 - 1.6. Higher values are possible but only with techniques for pushing them, like supplemental CO2. For most of us these values are reliable.

I notice you're jumping back and forth between ppm and EC so I assume you know how to convert the 500 method.

The runoff values can tell you some valuable things. An output lower than your input means the plant was hungry and is eating. An output higher indicates the nutrients are accumulating faster than they're getting eaten. And be careful taking readings before the coco is properly rehydrated because you can gat a false high or it can even hide the truth with a false low where solidified salts are hiding in dry patches.
 
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Ninjadogma

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#3
umcalculat said:
Runoff EC/PPM readings are generally not very reliable when you’re using organics, especially something like Biobizz Fish Mix. The reason is that a lot of what you’re adding isn’t immediately present as free ionic salts in the root zone in the same way mineral nutrients are. Microbial breakdown plays a big role, and that introduces a delay and a lot of variability.
Click to expand...

Microbe EC burns differently. The EC numbers are still valid but require a little interpretation. They can handle a higher EC produced by microbes but if that value is left high it will burn.... Differently and slower but it'll still burn. It just doesn't hit the plant right away the way liquid nutes EC does. That's why you don't need to immediately freak out when you come across a high value.
 
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Marmaloid

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#4
OutdoorGanja said:
Hey y'all,

I've been trying to follow the cocoforcannabis website advice regarding measuring runoff, and i have consistently been getting lower runoff ec, adding more feed each time to the point where im now feeding it at like 3.0 ec. My plant is around 4 weeks old, yesterday i fed her a solution of 1480ppm, which has almost DOUBLE of the recommended dose of my grow nutrient, and i got a runoff of 1180. And then today i noticed the slightest clawing and a burnt tip.

Im using organic biobizz fish mix, which im guessing might be the issue? is reading runoff ppm not accurate when using organics? Im thinking of just switching to coco specific mineral nutes as i already had a feeling the fish mix isnt doing much in coco. Love to hear what yall think about this
Click to expand...
Hi. I'm quite new to this and when I started off I was consistently getting lower EC output. After four attempts at it and getting better each time I found that the pots were not drying out enough to build up the output ec. I was feeding to often and not letting he pots dry enough, about 50%. I use canna coco and in veg I feed up to a max of between 1.2 and 1.4. When I wasn't drying out enough, I was same as you, input of 3.0 and still 0.6 out. I use leds so my room doesn't get that hot. I use a heater to counter act that but still only have to be feeding once every four days to build up the ec in the pot. You need to be letting the pots dry to some extent to get that ec up so you need to figure out how fast those pots dry and how often you need to feed.
I hope this helps.
 
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Marmaloid

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#5
Marmaloid said:
Hi. I'm quite new to this and when I started off I was consistently getting lower EC output. After four attempts at it and getting better each time I found that the pots were not drying out enough to build up the output ec. I was feeding to often and not letting he pots dry enough, about 50%. I use canna coco and in veg I feed up to a max of between 1.2 and 1.4. When I wasn't drying out enough, I was same as you, input of 3.0 and still 0.6 out. I use leds so my room doesn't get that hot. I use a heater to counter act that but still only have to be feeding once every four days to build up the ec in the pot. You need to be letting the pots dry to some extent to get that ec up so you need to figure out how fast those pots dry and how often you need to feed.
I hope this helps.
Click to expand...
P's I feed a lot more often in flower, depends on how high the output ec gets. I feed based on that out put. I'm currently in week four of flower and feeding every other day.
 
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Thread info

Replies 4
Views 545
Started Apr 27, 2026
Latest post May 17, 2026
Starter OutdoorGanja
Forum Coco Coir

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