Hi Emylia,
Hope you remember me from my post some weeks ago:
Stunted growth - a repeating problem I can not solve
While I am grateful for the watering advice you gave me (game changer), I did run into other issues down the road and am currently in a desperate situation once again.
With the right watering method, light intensity, VPD and C02 and other concerns out of the way, there is one last issue I can’t resolve – feeding and media EC monitoring.
Those last plants from the post that looked amazing after the correction in watering, eventually got badly burned in week 4 of flowering.
A total of 4 waterings starting week 1 of flower with around 500ppm (1.5L each) is all that took to almost kill them.
I guess I did not take into consideration that by increasing the amount of water from 0.5L to 1.5L per watering I am also increasing the total amount of nutrients, regardless of ppm concentration. By the end of week 4 lower leaves stated to yellow and by the time I made a runoff test I realized the media was already over 1800ppm and they were frying. I did flush them but the damage was done. Perhaps there were also netes left from veg.
My conclusion is that I need a method of knowing the EC in the media prior to every watering in order to ensure that I am not overfeeding. Does this make sense? I used to rely on set feeding schedule that I’ve adjusted (trial and error) in time but realized every batch runs differently and that can’t work without actual knowledge of the media EC.
As I started to make runoff tests for EC I stumbled upon a new issue I was not aware of. The Plagron Lightmix I use seems to have a 1000-1200ppm runoff right out of the bag. So now every time I put seedlings or repot plants into their final container, I need to take this ppm into consideration, which make the whole decision making every more difficult. To add to the problem the Lightmix is pre-fertilized with mineral nutes, while I use Plagron Alga series nutes which are organic.
Usually I don’t adjust the pH of the watering solution, however now that I know there is so much mineral nutes in the media I wonder if I should.
At some point I plan to change the Lightmix with Promix that is not fertilized and recommended for organic grow. But that will take some tests and time so now I have to deal with the Lightmix.
Long story short, how should I approach the media EC monitoring and if runoff test is the solution can you advice of the correct way to do it and what things I should consider. I also bought a Bluelab Pulse meter, so far it gives rather close readings to the runoff.
P.S I was wondering if there is any way I could contact you privately and share with you a brief document describing my process and principles. It’s a simple table that includes all parameters of the process. Hopefully you can spot some issues and give me some general advice. My final goal is to set a fixed production process that works and try to stick with it and not change it. Last couple of years of my life passed into experimentation, theories and guesswork and honestly, I am physically and financially exhausted and don’t know if I can keep going. And yet I feel I am one step away from success.
, wherever you are. You helped me so much without even knowing. Thank you
just stop a beat, hoping the best for her and her future and so sorry for her loss. 
