Cannabis Nutrient Schedule 2026: Week-by-Week Feed Chart for Soil, Coco & Hydro

The complete cannabis nutrient schedule for 2026 — week-by-week PPM targets for soil, coco, and DWC hydro, with pH ranges for every growth stage from seedling to flush.

Understanding NPK Before You Feed Anything

Every cannabis nutrient product shows three numbers on the label: N-P-K. These represent Nitrogen (N), Phosphorus (P), and Potassium (K) — the three macronutrients cannabis consumes in the largest quantities.

Nitrogen (N): Drives vegetative growth, chlorophyll production, and protein synthesis. Cannabis is nitrogen-hungry in veg and requires declining nitrogen through flower.
Phosphorus (P): Powers root development and bud/flower production. Critical in early flower. Often supplemented with "bloom boosters."
Potassium (K): Regulates water uptake, enzyme activation, and overall plant health. Elevated potassium throughout flowering helps bud density and trichome production.

The core feeding shift: High-N, low-P/K ratios dominate veg (e.g., 3-1-2). As you transition to flower, flip to low-N, high-P/K ratios (e.g., 1-3-2). Failure to reduce nitrogen in flower is one of the most common mistakes beginners make — it delays flowering and reduces bud quality.

PPM & EC: How to Measure What You're Feeding

PPM (parts per million) and EC (electrical conductivity) both measure the total dissolved solids in your nutrient solution — i.e., how strong your feed is. EC is the international standard; PPM is derived from EC using a conversion factor.

You need a digital TDS/EC meter to feed accurately. Guessing nutrient strength by following bottle directions alone leads to overfeeding — most bottle directions are written for maximum sales, not optimal plant health.

Soil Nutrient Schedule: Week by Week

Soil is the most forgiving medium for nutrients because the organic matter and microbial life buffer pH swings and nutrient excesses. Start at 25–50% of the manufacturer's recommended dose and adjust based on plant response and runoff PPM.

Weeks 1–2 (Seedling): Plain, pH-adjusted water only. Quality potting soil contains enough nutrients for 2–4 weeks. Starting nutrients on seedlings causes burn.
Weeks 3–4 (Early Veg): Introduce a balanced veg nutrient at 25% strength. Target runoff PPM of 400–600. Check runoff pH — soil target is 6.0–7.0.
Weeks 5–8 (Late Veg): Increase to 50–75% strength. High-N formula. Add cal-mag if using RO or soft water. Target runoff PPM 700–900.
Week 1–2 of Flower (Transition): Begin reducing N, increasing P and K. "Transition" or "bloom" formulas typically have NPK ratios around 1-3-2. Target runoff PPM 900–1,100.
Weeks 3–6 (Peak Flower): Full bloom formula at 75–100% strength. Add a bud enhancer/PK booster at weeks 4–5. Target runoff PPM 1,000–1,300.
Weeks 7–8 (Late Flower): Taper nutrients down. Runoff PPM 600–800. Plants begin showing natural yellowing as nitrogen is consumed — this is normal, not deficiency.
Final 1–2 weeks (Flush): Plain pH-adjusted water only. Depletes stored nutrients for a cleaner, smoother final product.

Coco Coir Nutrient Schedule: Why It's Different

Coco coir is a hydroponic medium — it contains zero nutrients and has a slight cation exchange capacity that binds calcium and magnesium. This makes coco fundamentally different from soil:

Key differences from soil:
1. Feed from seedling transplant — no 'settling in' period with plain water.
2. Always add cal-mag at 3–5 ml/gallon — coco locks out calcium and magnesium without supplementation.
3. pH target is 5.8–6.2 (lower than soil, same as hydro).
4. Feed at every watering — coco has no nutrient buffer. Skip a feeding and plants show deficiency within 24–48 hours.
5. Run to 20% runoff at each watering to prevent salt buildup in the medium.

Coco PPM targets are the same as the table above but start nutrients immediately at transplant (week 1 at 25% strength) rather than waiting for soil nutrients to deplete.

a coco-specific nutrient line Feed Chart: Week-by-Week ml/L Dosing

a coco-specific nutrient line is one of the most popular two-part nutrient systems for coco coir grows. Always use Part A and Part B in equal amounts — never mix them together in concentrated form. Add to water separately, then combine.

pH target with Canna nutrients: 5.8–6.2. EC is measured after mixing both parts.

Optional Canna additives: Cannazym (enzyme supplement, use throughout at 2.5 ml/L), Canna Boost (flowering accelerator, add weeks 3–6 of flower at 2 ml/L), and PK 13/14 (PK booster, use weeks 4–5 of flower at 1.5 ml/L). Do not use PK 13/14 alongside Canna Boost in the same feeding — stagger by day.

Hydro DWC Nutrient Schedule

Deep Water Culture (DWC) hydro is the fastest-growing medium for cannabis — roots directly in oxygenated nutrient solution with zero resistance to uptake. This speed means mistakes manifest faster, too.

DWC-specific considerations:
— pH target: 5.5–6.2 (tighter range than soil or coco). Check and adjust daily in early growth, every 2 days in flower.
— Water temperature: 65–68°F (18–20°C). Above 72°F promotes pythium (root rot). Use an aquarium chiller or frozen water bottles in summer.
— Reservoir change: Replace the full reservoir every 7–10 days in veg, every 5–7 days in flower to prevent pathogen buildup and nutrient imbalance.
— Start EC lower than soil/coco: DWC plants are extremely efficient at uptake. Begin at 50% of soil targets and increase based on plant response.

Always mix nutrients into RO or filtered water in this order: Cal-Mag → Part A → Part B → Additives → pH adjust. Never mix concentrated nutrients directly together.

Reading Your Plant: When to Adjust the Schedule

The schedule is a starting point. Your plant tells you when to adjust.

Dark green, clawing leaves: Nitrogen toxicity. Reduce N concentration by 25%. Check if you're using a veg formula during flower.
Yellowing between veins (interveinal chlorosis): Magnesium or iron deficiency — often a pH lockout issue rather than an absence of the nutrient. Flush and correct pH first.
Brown leaf tips: Nutrient burn. Runoff PPM is too high. Flush with plain water until runoff PPM drops 200–300 points.
Light green / pale leaves: Nitrogen deficiency (in veg) or natural nitrogen decline (in late flower). In veg, increase N. In week 6–8 of flower, it's expected and natural.

A dialed-in feed is one of the biggest levers on final harvest weight. Once your schedule is set, estimate what that setup should produce with our cannabis yield calculator.

Frequently Asked Questions

What nutrients does cannabis need at each growth stage?

Cannabis needs high nitrogen (N) with moderate phosphorus and potassium during vegetative growth. At the flip to flower, reduce nitrogen and increase phosphorus and potassium. During peak flowering (weeks 3–6), use a bloom formula with minimal N and high P/K plus a bud enhancer. In the final 1–2 weeks, flush with plain water to clear stored nutrients. Cal-Mag is essential throughout in coco or when using RO water.

What PPM should cannabis be at each stage?

Target PPM ranges (500 scale): seedlings 0–100 (water only), early veg 400–600, late veg 700–900, early flower 900–1,100, peak flower 1,000–1,400, late flower 600–800, and flush 0–100. These are runoff PPM targets for soil. For coco and DWC, start feeding earlier and monitor input vs. runoff PPM to detect salt buildup. Always use a calibrated TDS/EC meter to measure accurately.

How often should I feed cannabis in soil, coco, and hydro?

In soil: water when the top 2 inches are dry, feed every other watering (feed-water-feed-water). In coco: feed at every watering (coco has no nutrient buffer), water daily or twice daily in late flower. In DWC hydro: nutrients are always present in the reservoir — top off with nutrient solution daily and change the full reservoir every 5–10 days. Never let DWC reservoirs go more than 10 days without a change.

Do I need cal-mag for cannabis?

Cal-Mag (calcium and magnesium supplement) is essential when: growing in coco coir (which binds Ca and Mg), using reverse osmosis (RO) or very soft water (which contains no mineral hardness), or when growing in DWC hydro. Soil growers using tap water with moderate hardness often don't need supplemental cal-mag. Signs of deficiency include interveinal yellowing (Mg deficiency) and brown/bronze leaf spots (Ca deficiency).

What is the best pH for cannabis nutrients?

pH targets vary by growing medium: soil 6.0–7.0 (optimal 6.2–6.8), coco coir 5.8–6.2, and hydro DWC 5.5–6.2. pH outside these ranges causes nutrient lockout where nutrients are present but unavailable for uptake — the #1 cause of apparent nutrient deficiencies in indoor grows. Always pH-adjust your nutrient solution after mixing and before feeding. Use a calibrated digital pH meter and calibrate it monthly.

What is the a coco-specific nutrient line feeding schedule?

a coco-specific nutrient line are used in equal amounts at every feeding. Start at 1 ml/L each during seedling/clone stage (EC 0.8–1.0), increase to 2–3 ml/L in veg (EC 1.2–1.9), peak at 4 ml/L each during flowering weeks 3–6 (EC 2.2–2.6), then taper to 2.5 ml/L in late flower before flushing. Always add Cal-Mag at 1.5–2.0 ml/L throughout, as coco binds calcium. Target pH 5.8–6.2.

Can I use Canna nutrients in soil?

Yes — Canna makes Canna Terra Vega (for veg) and Canna Terra Flores (for flower) specifically formulated for soil. For soil, target pH 6.0–7.0 and start at 25% of the recommended dose, increasing based on plant response and runoff PPM. a coco-specific nutrient line is designed for coco coir and hydro, not soil — using it in soil can cause pH issues and nutrient imbalances due to its lower pH profile.

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