# SOP: Diagnose and fix nutrient burn (tip burn) in cannabis

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**Download the nutrient burn (tip burn) SOP checklist**\
A step-by-step checklist to diagnose tip burn in coco, pH → EC → environment.

<a href="https://docs.google.com/document/d/1Fyyhq-TJm4K5XayMg__tNjqAkYbhMLsolXHPpFSIZSM/copy" class="button primary">Download now</a>
{% endhint %}

### What “nutrient burn” actually is

“Nutrient burn” is a symptom (usually burnt tips/edges, clawing, slowed growth), not a single diagnosis. The same look can come from three buckets:

1. Root zone too strong (excess salts / high EC in the medium)
2. Uptake blocked (lockout from pH, root stress, irrigation swings)
3. Environment too harsh (light/heat/low RH driving stress)

Your job is to identify which bucket is active before you change feed strength.

### Tools you need (minimal)

* pH pen (calibrated)
* EC/TDS meter
* Thermometer at canopy (or IR gun)
* Way to estimate VPD (app/calculator) + RH sensor
* Optional: PPFD meter (or at least a reputable light map)
* Optional: substrate EC/pH sensor, cultivation logs

### Safety rules (don’t skip)

* Change one variable at a time (otherwise you won’t know what fixed it).
* Don’t “flush” aggressively by default, especially in coco. Use “flush-lite” (increase runoff) unless you’re in severe toxicity.
* Judge recovery by new growth, not damaged leaves (old damage won’t reverse).

## Mini SOP: 3-step diagnosis (the same order as your slides)

### Step 1: Measure runoff pH (coco)

Target: 5.6–5.9

Sample properly: measure feed pH/EC, then collect runoff from a normal irrigation event (not a panic flush).

#### If runoff pH is HIGH (too alkaline, eg \~6.1+)

What it usually means: uptake is reduced and plants can look “underfed” even if you’re feeding enough.

**Actions**

1. Fix pH first (bring runoff back into 5.6–5.9 over the next 24–72 hours).
2. If your input/feed EC isn’t excessive, don’t cut feed yet.
3. Reassess after pH is back in range.

**Do NOT**

* Drop EC hard while pH is off, you can starve the plant and slow recovery.

#### If runoff pH is LOW (too acidic, ≤ 5.4)

Go to Step 2.

### Step 2: If runoff pH is LOW (≤ 5.4), measure runoff EC (trend-based)

Don’t chase one number. Compare runoff vs input and watch the day-to-day direction.

#### Interpret it

* Runoff EC slightly above input can be normal.
* Runoff EC much higher than input and/or rising daily = salts building in the medium.

#### Actions (choose the smallest effective move)

**If runoff EC is high/rising**

1. Reduce feed strength one step (think 10–30%, not “nuke it”).
2. Increase runoff for a few irrigations (flush-lite): slightly larger shots or an extra event to wash salts out.
3. Keep pH in range while doing this.

**If runoff EC is normal**

* Don’t blame salts. Go to Step 3.

### Step 3: Rule out environment + watering

This is where most “EC problems” actually live.

#### A) Light/heat (canopy stress)

**Check**

* Measure PPFD + canopy temperature at the top of the canopy.
* Symptoms often worst on top leaves, closest to the light.

**Fix**

* Raise/dim lights, improve canopy air mixing, reduce hotspots.

#### B) Low RH / high VPD (plants “drink too hard”)

**Targets**

* Veg: 0.8–1.2 kPa
* Flower: 1.1–1.3 kPa (safer, less argument bait)

**Fix**

* Increase RH (or reduce temp), smooth swings at lights-on.

#### C) Watering/root stress (coco specific)

What causes “burn” even when feed looks fine

* Big drybacks or inconsistent irrigation timing can spike root-zone EC between feeds.

**Guidance (coco)**

* Avoid big drybacks. Aim max:
* 15–25% veg
* 25–35% flower

**Fix**

* More consistent irrigation events, avoid extreme drybacks, stabilise runoff %.

## Immediate response (when burn is actively getting worse)

Use this if you’re seeing new tips burning daily.

1. Stop changing multiple things.
2. Do the 3-step order above.
3. If Step 2 confirms salts building:
4. Reduce feed one step
5. Flush-lite (increase runoff) for 24–72 hours
6. If Step 3 confirms environment:
7. Fix light/VPD first before changing nutrition again.

## Recovery expectations (what “getting better” looks like)

* Mild: 7–14 days for new growth to look clean
* Moderate: 2–4 weeks
* Severe: up to 6 weeks

**Signs of recovery:**

* No new burn on new growth
* Leaves regain normal posture, and growth rate stabilises

## Common lookalikes (quick checks)

* Nitrogen toxicity: dark green + clawing (not classic tip burn)
* Overwatering: droop + yellow, slower growth, not crispy tips
* Light burn: top leaves paling/bleaching
* Deficiency patterns: more uniform chlorosis or interveinal yellowing vs “crispy tips”

## Prevention checklist (daily/weekly habit)

Daily

* Log feed pH/EC
* Spot-check RH/temp (and VPD if possible)
* Quick top-canopy visual check

Weekly

* Compare input vs runoff pH + EC from multiple pots/areas
* Check irrigation consistency + dryback %
* Confirm PPFD/temperature at the canopy hasn’t drifted

Optional high-precision

* Leaf tissue test when symptoms persist despite correct pH/EC and a stable environment.<br>

{% hint style="info" %}
**Download the nutrient burn (tip burn) SOP checklist**\
A step-by-step checklist to diagnose tip burn in coco, pH → EC → environment.

<a href="https://docs.google.com/document/d/1Fyyhq-TJm4K5XayMg__tNjqAkYbhMLsolXHPpFSIZSM/copy" class="button primary">Download now</a>
{% endhint %}