What is this...Help

What are these spots on leaves.. nutes are ff trio at half. Seems to be getting worse daily.

I see posts like this all the time in here & always followed by ‘feeding fox farms at half strength’. Could be coincidence but Im not convinced. & the logical is answer will always be the same, check flush, check ph, check run off ph & all are good answers & are usually followed up with yep flushed checked ph & all is good. So this puts into question fox farms nutes or the use of fox farms nuts at half strength. Now someones guna pop up & say Ive always used fox farms & never had an issue & thats all good & well, people don’t really post threads in here when their not having issues but 9 times out of 10 when someone is looking for advise on an issue its to do with fox farms nutes

The problem is bottled nutes.... period. jk...I know everybody loves their bottled nutes.

I'd scope for bugs before doing anything. Look underneath the leaves, and use the same scope you'd use to check trichomes.