Having some pretty bad issues. Help me out please?

Hey everyone! Im having a hard time nailing down what the issue in my room is. I'm NOT a soil grower and have been having problems with the ones in dirt. I don't think this is an over/under watering thing, but I suck with soil. Maybe a lockout? Here's the specs:

FFOF with 20% perlite
Ph water in: 6.3-6.5
Ph water out: 5.8
Plants are ~ 40 days old
Temps steady 70-75f 50%RH
Lights- hlg600 led
Multiple strains all same issues


I haven't been using any nutes right now because I've been told ffof is running hot nowadays. I was also seeing issues of N toxicity before, so I've been putting in straight RO water nothing else. Not even calmag or anything.

These issues have been bad the last week or two. This is happening to all my plants. I have some in 1G and some in 3G containers, so I'm hesitant to say it's a rootbound issue? There seems to be a host of deficiencies etc.

Visually, it looks like a watering issue, but they regardless of water content, they never seem to rebound. When I thought I was over watering, I let them dry out. No change. Same with vice versa. Any input on this would be great. Thanks!

Underfed.

High pH in the media causing a nutrient uptake issue? I would check the pH of the media, it's not always anywhere near what we are inputting.

You need to supply micros to your plant...especially if you're running with RO. You're short on Mg for starters, they look perhaps over watered and I'd get a handle on your pH; that's where I'd start. Good luck

I had plants do that exact same shit and testing the media proved the pH was up in the 8's.

Oh shit, just caught the no nutes part. FEED YOUR PLANTS

So I just went and bought a soil pH probe. Soil is sitting at around 7-7.3 pH depending on the pot

Well it thats an accurate meter then you are a little high. Assuming a target pH of 6.5, FEEDING (not plain water) at a pH of 6 - 5.7 would offset that pH and you should see immediate signs of nutrient uptake as the pH swings through the goldilocks zone between feedings, likely ending up a little lower before the next feeding. Then adjust the pH of the next feeding accordingly after checking the soil pH.

but you gotta put food in the water.