About plants with drooping yellow leaves and curly red leaves

[qq979146619]

As a novice grower, my negligence resulted in EC exceeding 4000 ppm and reaching 3000. After soil cleaning, I washed the EC value to 2000 ppm and reached 1200 Currently, my soil pH is 7. But I don't know why when I use nutritional feeding, the pH is 6.1, but after testing, the runoff reaches 7.2.. I hope experienced friends can provide some solutions. At present, my growth has been slow for almost two months. The nutrition I use is Fox Farm! How can I alleviate the current situation

[Bluey]

I don't pay too much attention to run off pH as I've found in my setup the results are not repeatable and therefore not very scientific. Also soil pH testers can be a bit inaccurate.

Your plants do have nute deficiency but the big Q is why?

As you say if you are in normal soil, runoff will wash the nitrates out of the soil. The light green you are seeing appears to be an N deficiency.

if you've flushed them well and your getting 1200EC run off try just feeding them water at pH 7 for a few feeds. Make sure to let the pot dry out between waters so you're not drowning them and no runoff as that runoff will contain the nitrates your plant needs.

[qq979146619]

That means currently I can dry the flowerpot between water. Feed more water and don't have to maintain runoff, right? Do I need to add nutrients when feeding water?

[Bluey]

I'd just use pH water. Don't do run off. You have washed all the nitrates from the soil with your flushing. If you don't see healthy new growth for a bit I'd add nutes at half the recommended dose fir that stage but I don't think you'll need it with that EC.