Very abnormal EC Runoff for CoCo Coir - please help on what I should do. I am scared to increase nutes in case I get nute burn

2ec is high for a soilless grow, expecially if TDS pen is on 500-scale.. 1000ppm is high 99/100 times. remember that people online reflect popular opinions, but not often educated opinions. Always find reputable verification. Avoid these forums, lol.. just shit info way too often. This tds pens are useless, lol. they don't measure ppm, they convert electrical conductivity. the fact there are 3-4 different conversion factors varying manufacturers of those pens use should tell oyu all you need to know about TDS readings. Your EC might be high due to something that isn't even plant-available or related to plants in the water. in soilless/hydro you can calculate exactly what the ppms are from your guarnateed labels. there are even apps that do it for you. this is what matters. If religiously giving 10% runoff, your substrate will keep a consistent equilibrium over time and buildup is not possible. any tox seen is guaranteed to require a formula change in that context. This makes diagnosing visible symptomsm much easier to deal with. No concern about build up fertigating properly.. Don't let it sit in its piss, for example.

Plants are looking healthy and well fed. If anything I'd say maybe a bit to much N. I have a feeling that the runoff your collecting is going though it to fast. or their is a dry spot in the pot. If you going in at 2EC and its coming out at 0.7, 0.4, 0.3 maybe it needs more runoff. Good amount is 10% of the pots volume. eg 2Gal or 8L aka 8000ml pot you want 800ml coming out. and watering in slowly. Also, going in at 2EC seems to high in veg, I would not be going over 1.4-1.6EC for the size of the plants, but that's just my opinion. let us know how much runoff you are getting with these plants. Good Luck!