CalMag issues, rust spots or rusting of the edge of leaves inward. Iāve been seeing a lot of these in āquestionsā. Too much K (potassium) will cause CalMag LOCKOUT! I know everyone wants huge buds, but donāt force something thatās not there. I havenāt read the diary or your feeding to know if thatās the issue, but a lot of ones Iāve been reading Iām pretty sure is the issue. If itās plant burn, then itāll be the tops or look like itās localized unless youāre absolutely frying your plants. Also another thing, if using tap water you need to know what your heavy on(usually itās cal) but if adding nutrients to tap water such as CalMag you could be supplying too much and that will cause lockout as well. If using RO donāt stick to that 3/4 feed.. give them the normal dose. If using tap water you need to find out how they treat your water and whether itās soft or hard. Just my two cents.. hope it helps!
Also just another quick tip, not all cities use chlorine, some use chloramine! Which is worse and harsh to plants. Are you using tap with this plant ;)