Preventing cannabis nutrient burn comes down to one habit: feed a measured, repeatable schedule that starts below the label's recommended strength and rises only when the plant asks for more. Nutrient burn is salt stress, not a virus, so the fix is arithmetic, not guesswork. Mix nutrients to a target EC or PPM, keep pH in range, alternate feedings with plain water, and test runoff weekly to confirm the root zone is not accumulating salts.
What causes nutrient burn in cannabis?
Nutrient burn happens when soluble salts build up faster than the plant and the medium can use them. Leaves respond with brown or yellow tips, a dark waxy sheen, and downward clawing at the leaf edges. Overwatering, feeding into bone-dry medium, and topping off reservoirs without dumping old solution all make the buildup worse.
How do you build a feeding schedule that prevents burn?
- Start at 25 to 50 percent of label strength. Manufacturer charts are written for heavy-feeding crops and peak vigor. Halve it for seedlings, clones, and any new strain you have not grown before.
- Set a fixed cadence. Feed, water, water is the safest rhythm in soil and coco. In drain-to-waste hydro, feed every irrigation but at lower EC.
- Raise strength in small steps. Increase EC by about 0.1 to 0.2 per week and hold each level for a full week before judging results.
- Never feed dry roots. Water the pot lightly first, then apply the nutrient solution, so concentrated salts do not hit bare root hairs.
- Taper through late flower. Peak feed lands around weeks 3 to 5 of flower, then drop back and finish with a plain-water flush.
What EC or PPM should you feed cannabis?
Common working ranges are 0.4 to 0.8 EC for seedlings and clones, 1.0 to 1.6 EC in vegetative growth, and 1.4 to 2.0 EC during peak flower. On the 500 scale, that is roughly 200 to 400 PPM early, 500 to 800 PPM in veg, and 700 to 1000 PPM in flower. Sativa-leaning and sensitive strains often finish best at the low end of those windows.
how to fix nutrient burn in cannabis plants
Why does pH belong in the same schedule?
Target 6.0 to 6.8 in soil and 5.5 to 6.5 in coco and hydro. Out-of-range pH locks out nutrients even when the EC looks correct, and the resulting symptoms are easily misread as burn. Recalibrate your meter every few weeks, since a drifting probe causes more feeding errors than any chart.
How do you read runoff to catch burn early?
Collect runoff once a week and compare its EC to what went in. A runoff reading more than about 0.3 EC above the input means salts are accumulating and the next watering should be plain pH-adjusted water. If runoff climbs two weeks running, cut feed strength by 20 percent rather than waiting for visible damage.
What should you do at the first sign of nutrient burn?
Stop feeding, irrigate with pH-corrected water until runoff runs close to input EC, then resume at half the previous strength. Flushing with two to three times the pot volume of water clears excess salts in a single pass. Damaged leaf tips will not repair themselves, so judge recovery by new growth instead.
Does a feeding log actually help?
Yes. Record date, product, EC, pH, runoff, and any change in appearance for every feeding. A log turns a vague symptom into a timeline you can trace, which is the difference between a two-day correction and a two-week stall.