Why do I have rapidly spreading yellow on my leaves?

LOL 'overwatering' in a dwc... c'mon. I want to know the dynamics of how that is possible! Initial best guess -- either rootzone (ph/infection) or the leaf is simply too close to the plastic there and fucking with transpiration. if it doesn't spread to other leaves and only happens to the ones nearly touching objects or other leaves, that becomes more likely. Is it only the leaves touching or nearly touching a surface? could be why. definitely inspect the roots for anything slimy or discolored (fertilizers can stain roots and that's okay if not slimy). Does look like rootzone issue. did it look like that as it was new growth? Some might be variegation if that is the case cal/mag is not a thing. There is calcium and there is magnesium. They are 2 unique nutrients with unique deficiency symptoms. This looks like neither. Download a leaf symptom chart - google image search can help. The symptoms and location don't really match up well with anything... double check that pH and inspect the roots. in dwc so compare to these ranges.. if anything drastically different, could help diagnose... but there are many variables that can make a different formula function fine despite being different from this: PPM Calculated from labels, not an incredibly inaccurate conversion of EC to ppm. N 120-130 P 40-60 K 180-200 Ca 100+ Mg 75ish S 100 because the ratio of nutes can impact needed ppm of a nute, other formulas can work fine, too. but if something stands out and correlates to a symptom on the leaf chart, that can give a bit more confidence in diagnosis. I don't see signs of toxicity, so i'm not feeling the lockout answer. 600-750 ppm of a well-balanced diet won't cause toxicities.

Have a look under the leaves I think you have bugs..

that does not look like CaMg to me. If anything its a PH flux or root rot issues.

yes to Nocone_Purple tap water 150 + 300 ppm veg fert it's not Ca

Hey there it’s almost 100% over watering. Let the soil get really dry then water… if not that it’s possible you spilled some water with nutrients directly on the leaf…. Good luck don’t worry plants are very resilient they will survive threw almost any

Looks more like early nutrient lockout than a Cal/Mag deficiency, especially since it got worse after feeding. Even if your pH seems fine, salt buildup in the medium can still block uptake. I’d suggest giving her a light flush with pH balanced water and then reintroduce nutes at half strength next watering Also make sure runoff EC isn’t too high that‘ll confirm if there’s buildup