Originally Posted by The.Cook
@miraculous med: I think he's feedin with same nutrient solution, from the younger to the oldest.
If it's not a "test error" due to run off evaporation, it could also mean your feeding to much (also with regard to water / nutes demand). Maybe plants are transpirating a lot for some reason, taking up lot of water but not so many nutes, whose remain in the ground... Just guessin anyway...
Thanks for the thoughts guys. The cook has it. I sometime test with pure RO when I have a new batch of coco. Yet to see higher than about 200, which I assume is pre-charge, so I don't flush.
I feed the same 6/9 ~ 650 PPM every day. All plants get the same, until last week when just that plant gets water.
I don't think evap answers this as I do the test within 5 minutes. Mix nutes, ph, measure ppm, water, collect runoff, measure ec.
If I had barely any runoff I think this would make sense. But as noted I get an average of 50%, which one would think would balance out the ions.
It is hot/dry here. I am in somewhat small pots and some do get a bit light by the next water. Perhaps its the transpiration that explains the increased ion concentration. Still, if that were the case you might expect nute burn or as a symptom I could drop feed strength.
But 6/9/650 PPM under a 600 W in a 2x3' area already seems a bit low....