PPM.help

if you don't feed every irrigation, it's some weighted average over time that results. runoff is not accurate as far as what exists in the substrate. When things are healthy, you can take some readings and find out what 'normal' is for runoff, but don't expect it to match what youf feed.. when it is further off or odd, then you can react. without a baseline when things are going smoothly, these readings are fairly useless with nothing to compare them to. Roots do not actively select what it allows in. Either it physically fits in through normal osmosis/diffusion, it's not entering. This is only relevant for some soil-nutes that will read higher EC/ppm in medium and runoff than what is actually useable and able to enter the plant. That is the only time how the plant drinks should effect ppm. Evaporation should not be a major factor in any proper context. if soilless, 10% runoff will maintain whatever equilibrium resutls inyour medium from your nutrient formula. The runoff being 'off' is merely what is achieved from the 10% runoff. Any buildup in the plant (shown by leaf symptoms) that results while adhering to this practice was not caused by the irrigation process but by a formula too high in something. This makes diagnosing easier. not sure what you are, but 85% promix is essentially soilless. you are providing 100% of plant needs in short order. practical example -- i feed at 1.3EC every irrigation with religious 10% runoff or more. I don't expect my substrate to be "1.3EC" but i know whatever equilibrium tht does result, it's at least in the proper ratio. I don't care if it is "1.3" or not in the substrate because that is absolutely not important. The resulting average over time will be consistent, that is the key. Observing and reacting to plant is all that needs to be done at that point. read plant.. that's how you tell. If solless, religious 10% runoff maintains consitent levels of nutrients in medium. if that is consistent, it makes diagnosing and reacting to issues much easier by eliminating a whole host of possible causes not realted to your forumal but to behaviour/practices related to irrgaation/fertigation.

Well depending how much runoff you fed to that could be from a few feedings ago but if ur feeding to 20% or so could just mean your plants are hungry, if the next feeding is the same u can prob bump it up more. In the rare that can happen with build up and the substrate isn't passing nutes threw. But that's a very rare case and you would be seeing other signs and issues if that's the case. But hopefully they are just hungry and you can go up a bit more, so that's a good thing you got hungry girls. 1100 ppm 700 scale? Or 500? And what stage are you at, if it's 700 I feed higher than that normally later on even more, also I am on photos, if your autos that's different can't really compare the 2 feedings. Autos are more sensitive than photos when it comes to EC/ppm