Crop Steering in coco. How to determine optimal EC?

[cannalyst]

The conductivity measurement isn't very useful beyond verification of a known solution.

In order to deliver precision nutrient you'd need to calculate for the elemental requirement of the plant and dose accordingly.

Nutrient lines abstract away this knowledge for profit and have everyone blindly dosing their crops to mixed effect.

 

[Ca++]

Dosing individual elements is awkward, even if you can measure what's been taken.
If we had the perfect feed to start with, the speed the plant takes each element, isn't equal. The K might be taken in hours, and putting it back at the rate it was vanishing, would be toxic. We see N studies of 160ppm in dwc, but that solution might last a week, with a top up solution being used, that doesn't have everything in it. If we keep N constant, it's more like 30ppm needed.

Now as we look at our commercial feeds, we should be able to see that one suited for 6 fertigations per day, may not be so suited for a DWC meant to run a few days. Some feeds will talk of using less EC with higher frequency fertigation. It's hard to be more specific with their formulations, as all our plants differ somewhat in their daily needs.

It's not all doom & gloom though. We have people here, doing well, with tanks set for long term us. There is an idea that the feed is either in the tank, or in the plant, it can't escape. So all you really need do is top up. Which they do with the same feed. It works. Though in fact, the top up feed should actually be a bit more specific. If we could formulate that. It has a name, but it's not engaging my brain right now