Hey all - started getting some brownish rust spots a few days ago…and they seem to be popping up with more frequency daily. Any ideas? Leaves seem to be curling up a touch now as well. Maybe a magnesium deficiency? Epsom salt foliar spray ok in mid flower? Pics below (didn’t do a great job focusing, sorry).
Medium/grow method: FFOF/Perlite; 3 gallon fabric pots.
Feed: 1/2 dose of Fox Farm Trio (just cut out the Grow Big last feed); full serving of CalMag every other feed (was doing 1/2 serving, but just upped it for feed last night thinking that might be my rust issue); 1/2 serving of Silica every other feed; 1/2 serving of Fox Farm Beastie Bloomz for last 2 feeds; full serving of Mammoth P. Last feed was 760 PPM, pH 6.3; runoff was 840 PPM, pH 6.3. Feed, water, feed, water (every other other day). Runoff to about 15%. I flushed with pH’d water 2 weeks ago – just to reset the medium a bit (per FF soil schedule).
water source: city water; runs a little acidic, so usually have to PH down to about 6.3-6.5.
Strain/age: Blueberry Auto ILGM. Week 9. Been flowering for about a month I guess.
Light: HLG 260xl - about 18 inches at 160 Watts; 20/4 light schedule
Climate: Indoor Tent; running a Cloudline T6 inline exhaust fan with Carbon Filter; passive intake; couple desk fans pushing air around; Temps: 75 during the day; 65 at night; RH: 38-48.