@ fdd or anyone who can help. im growing ak47. ive got some grow years under my belt. every crop @ 3rd wk 12/12 i get what looks like fert burn that starts on the tip of fan leaves then proceeds along the outer edge before closing in on the middle. my response is to up the nutes listening to guy @ grow store saying its a phos def. every crop with different nutes. ive used ionic ,gh ,fish emulsion and now age old. 4 gal bucket pro mix. feed ph 6.2 2-3 Tbsp gallon age old bloom with fossil fuel ,nitrozyme, greenfuse bloom booster all at full strength every watering and when i notice the problem a little cal-mag. is that clear enough?
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Tre274.... Plain & Simple - Overkill.... Sounds like your soil is overstocked on nutes (semi-toxic) and your pH is probably in the dead zone.
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Check your soil pH first..... then get ready for some flushing.
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pH some water to correct the high pH, which is locking out nutes and causing signs that are easily misread as other problems.
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If you soil pH is over 7 (did I say if ?), flush with water pH'd to 5.8. Flush repeatedly, until the pH of the runoff water is 6.5 or under.
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Then wait two days and resume a simple flowering (feed schedule), use some cal-mag and your basic bloom fert (at 1/2 strength), leave all the other stuff out.
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Then as the soil needs water, water with pH adjusted water in the 5.8 to 6.2 range. Water, Water, Feed in rotation. Slowly bump up the feeding strength. Leave all the extras out.
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Hope this helps....
Keep it Real...Simple... cause simple is Best......
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