Calculateur de Nutriments Cannabis
Calculate a stage-based cannabis feeding recommendation for soil, coco, or hydro setups, including EC and PPM targets. Built from real growing data to help you feed smarter — not harder.
Quick Cannabis Feeding Answers
Calculer Votre Plan de Nutrition
Quick Feeding Answers
Seedling EC?
0.2–0.5
Very light — most soils provide enough
Flower PPM?
600–1000
Varies by medium and stage
Soil vs Coco?
Less vs More
Soil buffers more, coco needs daily feed
Autoflower feed?
20% Less
Lighter than photoperiod plants
How the Cannabis Nutrient Calculator Works
This tool uses your plant's growth stage and growing medium to estimate a practical feeding range. Rather than generic feeding charts that apply the same numbers to every situation, our calculator adjusts recommendations based on whether you grow in soil, coco coir, or hydroponic systems — because each medium handles nutrients very differently.
EC (electrical conductivity) and PPM (parts per million) are the two primary measurements growers use to gauge nutrient strength. Our calculator provides target ranges for both, along with feeding frequency, nutrient emphasis, and flush timing. The ranges are deliberately conservative — starting lower and increasing gradually is always safer than starting too strong. If you select autoflowering seeds, the calculator automatically reduces recommendations by 20% to account for their lighter feeding requirements.
Cannabis Feeding Schedule Generator — Soil, Coco & Hydro
Our calculator creates personalized feeding schedules based on your specific growing medium and plant stage. Unlike static feeding charts, the schedule generator accounts for whether you grow in soil (less frequent, buffered feeding), coco coir (daily feeding with runoff monitoring), or hydroponic systems (continuous feed with tight EC management).
The generated schedule includes feed frequency, nutrient strength targets (EC and PPM), stage-specific nutrient emphasis (nitrogen for veg, phosphorus and potassium for flower), and flushing guidance. Growers using autoflowering cannabis seeds receive automatically adjusted schedules with 20% lower nutrient concentrations to match their lighter feeding requirements. Scroll up to the calculator to generate your custom feeding schedule.
Cannabis Feeding by Growth Stage
Cannabis nutrient requirements change dramatically as plants progress from seedling to harvest. Understanding what your plant needs at each stage is the foundation of successful feeding.
| Stage | EC Range | Primary Focus | Key Nutrient |
|---|---|---|---|
| Seedling | 0.2–0.5 | Root development | Very light / water only |
| Early Veg | 0.6–1.0 | Leaf & stem growth | Nitrogen (N) |
| Late Veg | 0.8–1.4 | Vigorous canopy | N with increasing P |
| Early Flower | 1.0–1.6 | Transition to bloom | P & K increasing |
| Mid Flower | 1.2–2.0 | Bud development | P & K dominant |
| Late Flower | 0.6–1.2 | Ripening & flush | Reduced / flush |
Seedlings need almost no external nutrients — most quality soils provide enough for the first 2-3 weeks. Vegetative plants demand nitrogen for leaf and stem development. The flowering stage shifts demand toward phosphorus and potassium for bud formation. Late flower involves reducing nutrients and often flushing with plain water to improve final product quality. Harvest timing and final flush duration vary by medium and grower preference.
Soil vs Coco vs Hydro — Feeding Differences
🌍 Soil
- • Built-in nutrient buffer
- • Feed every other watering
- • Most forgiving medium
- • Natural pH stability
- • Best for beginners
🥥 Coco Coir
- • No nutrient buffer — feed every watering
- • Needs cal-mag supplementation
- • Faster growth than soil
- • Monitor runoff EC closely
- • Best for yield-focused growers
💧 Hydroponic
- • Most precise nutrient control
- • Continuous feed via reservoir
- • Fastest growth rates
- • pH and EC must be monitored daily
- • Best for experienced growers
Soil naturally buffers nutrients, making it the most forgiving medium for beginners. Coco coir is an inert medium that requires consistent feeding at every watering — it offers faster growth but less margin for error. Hydroponic systems deliver nutrients directly to roots with maximum efficiency, producing the fastest growth and highest yields, but requiring the most knowledge and monitoring.
| Factor | Soil | Coco | Hydro |
|---|---|---|---|
| Feed Frequency | Every 2-3 days | Daily | Continuous |
| EC Range (Flower) | 1.0-1.6 | 1.4-1.8 | 1.6-2.0 |
| Nutrient Buffer | High (forgiving) | None | None |
| Growth Speed | Moderate | Fast | Fastest |
| Difficulty | Beginner | Intermediate | Advanced |
| Cal-Mag Needed? | Rarely | Always | Often |
| Best Strains | Forgiving autos | High-yield indoors | Performance strains |
Your medium choice should match your experience level and how much time you can dedicate to plant care. Beginner-friendly autoflower strains in soil offer the most forgiving combination. High-yield strains in coco or hydro deliver the biggest harvests for experienced growers willing to invest in precise nutrient management.
What Is the Best EC and PPM for Cannabis?
The ideal EC and PPM depend on your plant's growth stage. Here are the target ranges most growers use across all mediums:
🌱 Seedling EC & PPM
0.2–0.5 EC / 100–250 PPM
Seedlings need almost no nutrients. Most quality soils provide enough for the first 2-3 weeks. In coco or hydro, start with a very dilute solution. Overfeeding seedlings is the most common beginner mistake.
🌿 Vegetative EC & PPM
0.6–1.4 EC / 300–700 PPM
Veg plants need increasing nitrogen for leaf and stem growth. Start at the low end of the range during early veg and increase through late veg as the plant builds its canopy. High-yield strains can handle the upper range.
🌸 Flowering EC & PPM
1.0–2.0 EC / 500–1000 PPM
Flowering demands peak nutrition, especially phosphorus and potassium. EC peaks during mid-flower (weeks 4-6 of bloom) then drops as you approach harvest and begin flushing. Hydroponic growers can push toward the higher end; soil growers should stay moderate.
Autoflowering cannabis strains need approximately 20% less than these ranges at every stage. Always start at the lower end with a new strain and increase based on plant response — it is much easier to add more nutrients than to recover from overfeeding.
EC vs PPM for Cannabis — Which Should You Use?
📊 EC (Electrical Conductivity)
- • Universal standard worldwide
- • No scale confusion
- • Preferred by professional growers
- • Measured in mS/cm
- • More precise for nutrient control
📏 PPM (Parts Per Million)
- • Populaire aux Etats-Unis
- • Two scales exist (500 and 700)
- • Easier to understand conceptually
- • Convert: EC × 500 = PPM (500 scale)
- • Always confirm which scale your meter uses
Our recommendation: Use EC if your meter supports it — it eliminates the confusion between PPM scales and is the standard used by commercial cultivators worldwide. If you prefer PPM, the 500 scale is the most common internationally. Our calculator provides both values for convenience. The key takeaway: whether you use EC or PPM, consistency and monitoring plant response matter more than hitting an exact number.
EC and PPM Explained for Cannabis Growers
EC (Electrical Conductivity) measures the total dissolved mineral content in your nutrient solution. Higher EC means more concentrated nutrients. It is measured in millisiemens per centimeter (mS/cm) and is the most universal measurement used by cannabis growers worldwide.
PPM (Parts Per Million) is another way to measure nutrient concentration. There are two PPM scales: the 500 scale (multiply EC by 500) and the 700 scale (multiply EC by 700). Our calculator uses the 500 scale, which is the most common internationally. When reading PPM values from other sources, confirm which scale they use.
Ranges matter more than exact numbers. Every strain, environment, and water source creates slightly different conditions. A grower using hard tap water (200+ PPM base) will need to account for those dissolved minerals before adding nutrients. A grower using RO or distilled water starts from near zero. Our calculator provides ranges — start at the lower end and increase only if plants show hunger signs like light green new growth or slowed development.
Common Cannabis Feeding Mistakes
Starting Too Strong
The most common mistake. Seedlings need almost no nutrients. Start at 25% of label dose and increase gradually. More plants are damaged by overfeeding than underfeeding.
Feeding Seedlings Like Adults
Seedlings have tiny root systems that cannot process concentrated nutrients. Wait until you see 3-4 true leaf sets before introducing any feed. Quality soil provides enough for the first 2-3 weeks.
Ignoring Runoff in Coco
Coco growers must check runoff EC regularly. If runoff EC exceeds input EC by more than 0.3, salts are accumulating. Flush with half-strength nutrients until runoff normalizes.
Confusing Deficiency and Toxicity
Nutrient burn (toxicity) and nutrient lockout often look similar. Before adding more nutrients to fix a deficiency, check your pH and EC first. The issue is often lockout, not shortage.
Same Feed for Every Medium
Soil, coco, and hydro have fundamentally different feeding requirements. A feed schedule designed for soil will underwater coco plants, and a hydro schedule will burn soil plants.
Not Adjusting for Autoflowers
Autoflowers need roughly 20% less nutrients than photoperiod plants. Their shorter lifecycle and smaller root systems make them more sensitive to overfeeding.
How to Choose Strains for Your Feeding Style
Not all cannabis strains handle nutrients the same way. Some are heavy feeders that reward aggressive nutrition programs with massive yields. Others are sensitive to overfeeding and prefer lighter, more conservative schedules. Matching your strain selection to your feeding style — or vice versa — is one of the most overlooked factors in growing success.
Autoflowering strains generally need lighter feeding due to their shorter lifecycle and smaller root systems. High-yield strains like Big Bud and Critical Mass are heavy feeders during bloom and reward structured feeding programs. Beginner-friendly strains like Northern Lights and White Widow are forgiving of feeding mistakes — they tolerate both slight overfeeding and underfeeding without major stress.
If you are new to nutrients, start with forgiving genetics in soil. If you are chasing maximum yields in coco or hydro, choose strains bred for heavy production and feed them precisely through bloom. Use our strain finder quiz or yield calculator to find genetics matched to your growing goals.
Cannabis Feeding Chart by Week
This week-by-week feeding chart provides general EC and PPM targets for cannabis grown in soil. Coco coir growers should increase EC by 0.2-0.4 and feed more frequently. Hydroponic growers can increase EC by 0.3-0.5 with continuous feeding.
| Week | Stage | EC (Soil) | PPM | Focus |
|---|---|---|---|---|
| Wk 1-2 | Seedling | 0.0-0.4 | 0-200 | Water only or very light feed |
| Wk 3-4 | Early Veg | 0.6-0.8 | 300-400 | Nitrogen for leaf growth |
| Wk 5-6 | Late Veg | 0.8-1.2 | 400-600 | N with increasing P, training |
| Wk 7 | Transition | 1.0-1.4 | 500-700 | Switch to bloom nutrients |
| Wk 8-9 | Early Flower | 1.2-1.6 | 600-800 | P & K increasing, bud sites |
| Wk 10-11 | Mid Flower | 1.2-1.6 | 600-800 | Peak P & K, bud fattening |
| Wk 12 | Late Flower | 0.6-1.0 | 300-500 | Reduce feed, begin flush |
| Wk 13+ | Flush | 0.0 | 0 | Plain water 5-10 days |
Autoflowering strains follow a compressed version of this schedule, typically finishing by week 10. Reduce all EC values by 20% for autoflowers. High-yield strains can handle the upper end of these ranges during peak flower.
Example Cannabis Feeding Plans
Here are sample feeding plans for the most common growing setups. Use our calculator above for a plan customized to your exact stage and medium.
Soil — Late Veg Feeding Plan
Nitrogen dominant with increasing phosphorus. Focus on building strong canopy structure before flip.
Coco Coir — Mid Flower Feeding Plan
Heavy phosphorus and potassium for bud development. Maintain cal-mag. Monitor runoff EC weekly.
Hydroponic — Early Veg Feeding Plan
Nitrogen dominant for rapid vegetative growth. Change reservoir every 7-10 days. Monitor pH daily.
Autoflower — Full Cycle (Soil)
Start very light, peak at week 5-6 of flower, then reduce. Autoflowers need 20% less than photoperiod.
Beginner vs Advanced Cannabis Feeding
🌱 Beginner Feeding Approach
- • Start at 25-50% of label dose
- • Use soil for natural buffering
- • Feed every other watering
- • Choose forgiving autoflower strains
- • Watch for leaf tip burn as first sign of excess
- • When in doubt, use less — not more
🌳 Advanced Feeding Approach
- • Push EC to strain-specific limits
- • Use coco or hydro for precision control
- • Feed daily or continuous recirculating
- • Choose heavy-feeding high-yield strains
- • Monitor runoff EC and pH at every feed
- • Fine-tune ratios by growth stage
Most growers should start with the beginner approach and progress to advanced techniques over multiple grows. The biggest mistake is jumping to aggressive feeding before understanding how your specific strain, environment, and water source interact. Our nutrient calculator adjusts recommendations for your experience level — beginners get conservative ranges that prioritize plant safety.
How to Increase Cannabis Yields with Proper Feeding
Proper nutrition is one of the three pillars of yield optimization — alongside lighting and plant training. Even the best genetics cannot reach their yield potential without adequate nutrition through the flowering stage.
During mid-flower (weeks 4-6 of bloom), high-yield cannabis strains demand peak phosphorus and potassium levels to support bud development. Growers who maintain consistent, adequate feeding through this critical window see 20-40% more yield than those who underfeed or feed inconsistently. The key is not maximum strength — it is consistent, stage-appropriate nutrition.
Use our yield calculator to estimate your harvest potential, then match it with the feeding plan from this nutrient calculator. Together, these tools help you plan both your genetics and your nutrition for maximum results.
Cannabis Nutrient Deficiencies and Feeding Issues
Even with a good feeding plan, deficiencies and toxicities can occur. Learning to identify and correct common issues is essential for every grower. Most problems are caused by pH imbalance or overfeeding — not actual nutrient shortage.
Nitrogen Deficiency
Lower leaves yellowing
Read guide →Phosphorus Deficiency
Dark purple stems, slow flower
Read guide →Nutrient Burn
Brown crispy leaf tips
Read guide →Nutrient Lockout
Multiple deficiency signs at once
Read guide →Calcium Deficiency
Brown spots on leaves (coco)
Read guide →Overwatering
Droopy leaves, slow growth
Read guide →Why Your Cannabis Plants Are Not Responding to Nutrients
If your plants look unhealthy despite regular feeding, the problem is rarely a nutrient shortage. The most common causes are pH imbalance, overfeeding, wrong medium strategy, or environmental stress. Before adding more nutrients to fix a problem, work through this checklist:
⚠️ pH Is Wrong
Cannabis absorbs nutrients within a narrow pH range (6.0-6.5 in soil, 5.5-6.0 in coco/hydro). Even with perfect EC, wrong pH causes lockout where the plant cannot access available nutrients. Always check and adjust pH before suspecting a deficiency.
🔥 You Are Overfeeding
More nutrients does not mean more growth. Excess salts damage root tips, reduce water uptake, and cause burn. Signs include dark green leaves, leaf tip burn, and crispy edges. Flush with plain water and reduce feed strength by 25-50%.
🌍 Wrong Medium Strategy
Feeding soil like coco (daily) causes waterlogging and root rot. Feeding coco like soil (every few days) causes dry spots and salt accumulation. Each medium requires its own frequency and strength approach.
🌱 Root Zone Problems
Compacted soil, root-bound pots, poor drainage, or cold root zones all prevent nutrient absorption regardless of what you feed. Healthy roots = healthy uptake. Check your container size, drainage, and root zone temperature (65-75°F ideal).
If you have ruled out pH, overfeeding, and root zone issues, the problem may be genetic. Some strains are simply more sensitive to certain nutrients. Forgiving autoflower strains like Northern Lights Auto and White Widow Auto tolerate a wider range of feeding mistakes, making them ideal for growers still learning nutrient management.
Why Trust Our Cannabis Feeding Recommendations
Our nutrient calculator is built on real growing data from 200,000+ growers across Europe who have used seeds from Royal King Seeds across soil, coco coir, and hydroponic systems. The EC and PPM ranges reflect what actually works in practice — not theoretical maximums from nutrient company marketing.
We deliberately use conservative ranges because real-world growing conditions vary enormously. Your water source, room temperature, humidity, pot size, and specific strain genetics all influence nutrient uptake. A recommendation that is too aggressive causes more damage than one that is slightly low — plants recover quickly from mild underfeeding but slowly from overfeeding and salt buildup.
Our feeding data is updated regularly based on customer feedback, new strain releases, and evolving best practices in cannabis cultivation. Every recommendation is designed to be practical, safe, and effective for home growers across France and Europe. For personalized growing support, our team is available through our contact page.