pH lockout in cannabis
What it looks like
Several deficiencies show at once even though you are feeding. New and old growth both look wrong. The nutrients are in the pot. The root-zone pH is outside the range the plant can use.
What usually causes it
Measure runoff pH, not just the water going in. Soil target is about 6.0–6.5. Coco and hydro about 5.8–6.2. Flush with pH-adjusted water, then feed at half strength. Do not add five bottles at once.
Check this first
Several deficiencies at once, or a hungry look in a pot you know is fed. This is the one to check before any of the others. Runoff pH out of range means the plant cannot use what is already there.
This is identification for a home grow. It is not a pesticide label and not medical advice. Follow your local law.