Guides
Grow with science, not myths
Technical guides based on a review of 130+ scientific studies. No hype: every figure with its source. Ver en español →
Iron Deficiency in Cannabis: EDDHA vs EDTA and Why Your Chelate Matters
Iron can be sitting in your reservoir and still never reach the plant. The difference comes down to your chelate and your water's pH.
Read guide → ClimateVPD Chart for Cannabis: Optimal Ranges by Stage and How to Dial It In
Vapor Pressure Deficit (VPD) is the single climate variable that most impacts nutrient uptake and plant health — learn how to measure and adjust it for every stage of your grow.
Read guide → FundamentalspH and EC in Cannabis Growing: What They Measure and How to Dial Them In
pH determines whether your plant can absorb each nutrient; EC measures total dissolved salts. Nail both — and calibrate your meter — and you'll dodge most nutrient problems before they start.
Read guide → FeedingCannabis Feeding Schedule: How Much Nutrient per Stage
There's no single mL/L number that works for every situation. What does exist are stage-validated EC targets and a calculator that converts them into a real dose based on your water.
Read guide → NutrientsNitrate vs Ammonium Nitrogen in Cannabis: Why the N Source Matters
Not all nitrogen is created equal: whether it comes as nitrate or ammonium changes what your plant can do with it — and can wreck your cal-mag balance in coco or hydro.
Read guide → CycleCannabis Seedling: The First 14 Days (Germination to Established Seedling)
The first 14 days determine your final yield. Real numbers by substrate: temperature, pH, EC, and the most common mistakes that kill seedlings before you even notice something went wrong.
Read guide → DiagnosisHow to Read Your Plant: Spotting Nutrient Deficiencies in Cannabis
Reading your plant starts with one question: is the symptom on old leaves or new growth? That distinction tells you whether the nutrient is mobile or immobile — and it changes the entire diagnosis.
Read guide → DiagnosisCannabis Nutrient Deficiencies: Antagonisms and pH Lockout
Most visible deficiencies aren't actually a lack of nutrient — they're an excess of another one or a pH out of range. Before you add more feed, diagnose the root cause.
Read guide → TechniquesCannabis Training and Pruning Techniques: Evidence-Based Guide
Not every training and pruning technique has the same level of evidence behind it. Some have peer-reviewed papers, some are solid grower consensus, and several haven't been studied in any plant species at all. Here's which is which.
Read guide → MediumSoil vs. Coco vs. Hydro: Which Growing Medium Should You Choose?
Soil, coco, and hydro each have real advantages and real limitations. The key isn't the medium — it's the management. There's no magic substrate.
Read guide → FundamentalsHow to Evaluate a Cannabis Fertilizer
Before you buy a fertilizer, check three things on the label: nitrogen form, iron chelate type, and whether the manufacturer cites their sources. Everything else comes after.
Read guide → Environment13/11: The Photoperiod That Outyields 12/12
One extra hour of light during flower yielded 35–50% more dry weight in a 2024 peer-reviewed study — with the same potency or higher. It's not for every strain: here's how to test it properly.
Read guide → DiagnosisYellow Leaves on Cannabis: Diagnosis in 3 Steps
Yellow leaves are alarming, but adding more fertilizer before diagnosing is the most common mistake growers make. Symptom location and pH are the two data points that change everything.
Read guide → DiagnosisCannabis leaf tip burn: causes and how to stop it
Tip burn is one of the most common symptoms in indoor grows. The first step is always to measure EC — not add more nutrients.
Read guide → DiagnosisNutrient Lockout in Cannabis: When Your Plant Can't Absorb
Your reservoir can be full and your plant still absorb nothing. Nutrient lockout is almost always a pH issue, not a missing nutrient.
Read guide → CareOverwatered Cannabis: The Problem That Looks Like a Deficiency
Overwatering isn't about dumping too much water at once — it's about not letting the medium dry between waterings. Without wet/dry cycles, roots suffocate and the plant looks exactly like it has a nutrient deficiency.
Read guide → Plant healthBud Rot (Botrytis) in Cannabis: How to Prevent Gray Mold
Bud rot can destroy a cola in days. Understand the two conditions that trigger it and how environmental management reduces incidence by 66% to 92%.
Read guide → Plant healthSpider Mites on Cannabis: Detection and Environmental Control
Spider mites multiply faster than you can see them coming. Above 77°F (25°C) and below 40% RH they can go from egg to adult in under a week — environmental control hits before any miticide does.
Read guide → MediumWhy Coco Coir Demands More Calcium and Magnesium: CEC Explained
You can mix a spot-on feeding recipe and still see calcium and magnesium deficiencies in coco. The reason is substrate chemistry: coir's CEC captures divalent cations before they ever reach the root zone.
Read guide → Organized growingNutrition for Medical Cannabis Grows Under Argentina's REPROCANN Program
In an organized grow under Argentina's REPROCANN program, formulation consistency and input traceability aren't a bonus — they're part of your recordkeeping. This guide starts there.
Read guide → EnvironmentCO2 for Indoor Cannabis: Photosynthesis, PPM Ranges, and Safety
Higher CO2 boosts photosynthesis in C3 plants like cannabis, but only when light is not the limiting factor. The range with the best evidence is 700–1000 ppm. Meta-analyses on C3 plants in general show biomass can improve 20–40% when CO2 is elevated; the specific dry-flower yield data for cannabis comes from a master's thesis (not peer-reviewed), not from controlled studies in an indexed journal. CO2 is odorless, heavier than air, and dangerous without monitoring.
Read guide → DiagnosisCannabis Nitrogen Deficiency: Signs and How to Fix It
Nitrogen is mobile inside the plant — when it runs short, the bottom leaves yellow first. Learn to tell it apart from normal late-flower senescence and how to fix it without burning your roots.
Read guide → DiagnosisCannabis Phosphorus Deficiency: How to Identify It
Old leaves darkening, edges bronzing, growth stalling — phosphorus deficiency has clear signs, but cold temps and genetics can mimic it. Learn to tell them apart before adding any nutrients.
Read guide → DiagnosisPotassium Deficiency in Cannabis: Burnt Leaf Edges
Burnt edges on older leaves often point to potassium, but the real cause is rarely a K shortage in your reservoir — it's pH out of range or another cation locking out potassium.
Read guide → DiagnosisCannabis Magnesium Deficiency: Interveinal Chlorosis Explained
Green veins, yellow blade, always starting from the bottom. Magnesium deficiency is one of the most common issues in coco and soft-water grows — and one of the easiest to mix up with iron deficiency.
Read guide → NutrientsCannabis Vegetative Nutrition: N, EC, and pH
In veg your plant is building branches, leaves, and roots at full speed. Dialing in N, EC, and pH is the foundation that gets her to flower in strong shape.
Read guide → NutrientsCannabis Flowering Nutrition: The PK Myth Debunked
More PK doesn't mean bigger buds. Excess phosphorus locks out iron and zinc, and the plant's actual P demand during bloom is far more modest than booster marketing would have you believe.
Read guide → Complete guideCannabis Nutrition: The Complete Guide
Most "nutrient problems" are actually pH issues or antagonisms. This guide covers everything: what each element does, what pH range you need by substrate, and how to read your plant before adding anything.
Read guide → DiagnosisCannabis Calcium Deficiency: Symptoms, Causes, and How to Fix It
Calcium can be in your reservoir and the plant still show necrosis — calcium immobility and low VPD are the two causes almost nobody checks first.
Read guide → DiagnosisCannabis Micronutrient Deficiencies: Zinc, Manganese, Boron, and Sulfur
The nutrient can be sitting right in your reservoir or substrate and still never reach the plant. Most micronutrient "deficiencies" in cannabis are actually nutrient lockout caused by pH — not a missing product.
Read guide → NutrientsCarbohydrates in cannabis: what they actually do during flowering
Sugars don't feed the plant directly — they feed the substrate microbiome, which in turn releases nutrients into forms the roots can actually absorb.
Read guide → FundamentalspH Regulators: When to Use Mineral vs. Organic
Dropping pH with whatever you have on hand works — until it doesn't. In soil, a strong mineral acid kills the microbiome. In hydro, organic acids sometimes can't hold the correction.
Read guide → NutrientsAutoflower Nutrients: Dosing, Cycle, and the 3-Base System
Autos burn at doses a photoperiod plant wouldn't even notice: the compressed cycle and smaller size completely change how you feed them.
Read guide → FeedingCannabis Week-by-Week Feeding Chart (13-Week Photoperiod)
There's no "one base per stage" rule: ALPHA, BETA, and GAMMA run together through the entire cycle — what changes is the ratio. This chart tells you when and how much of each product, week by week.
Read guide → Buying guideWhich Helix Kit Should You Choose? A Guide by Growing Medium
Choosing a kit isn't about brand loyalty — it's about your growing medium. Each system has different requirements, and the product that looks like "extra" in one kit is pure chemistry in another.
Read guide → SanidadCannabis pests and diseases: the most common ones and how to prevent them
Spider mites, thrips, whitefly, powdery mildew, botrytis: every pest has its own environmental window. Understand the VPD-pathogen relationship, apply solid prevention practices, and act with the stepped IPM framework before the problem escalates.
Read guide → SanidadThrips on Cannabis: How to Identify and Eliminate Them (Frankliniella occidentalis)
Thrips are 1–2 mm insects that scrape leaf cells and suck out the contents, leaving silvery spots and small black dots of excrement. In flower they can cut yield by over 30% and reduce THC content. Here you'll find the full IPM protocol, with a focus on biological control and the hard restrictions for late flowering.
Read guide → SanidadWhitefly on Cannabis: How to Identify It, What Triggers It, and How to Eliminate It with IPM
Whitefly is one of the most common pests in indoor and greenhouse cannabis. It sucks phloem, causes sooty mold, and — in the case of Bemisia tabaci — transmits viruses. This article explains how to detect it early, what conditions favor it, and how to manage it with a stepwise IPM protocol that goes from prevention to biological control, with chemistry as a last resort.
Read guide → SanidadPowdery Mildew on Cannabis: How to Identify It, When It Strikes, and How to Get Rid of It
Powdery mildew is the most common fungal infection in enclosed grow rooms. It shows up as white, flour-like spots on the upper surface of leaves, and if it reaches the buds during flowering, that part of the harvest is not recoverable. The good news: with strict environmental control and early action, it can be managed and prevented.
Read guide → SanidadAphids on Cannabis: How to Identify and Eliminate Them (Complete IPM Guide)
Aphids are one of the most common pests in indoor cannabis. They multiply fast, produce honeydew, and can vector viruses. This guide explains how to identify them, what conditions trigger population explosions, and how to eliminate them with a step-by-step IPM protocol.
Read guide → SanidadFungus Gnats on Cannabis: Sciaridae, Overwatering, and Step-by-Step Control
Fungus gnats get in through the door of overwatering. Letting the top 3–5 cm of substrate dry between waterings is the single most effective measure available — no product required. This guide covers the Bradysia spp. life cycle, how to detect them early, and the complete stepped IPM protocol for both vegetative and flowering stages.
Read guide → SanidadMealybugs on Cannabis: How to Identify Them, What Conditions Favor Them, and How to Eliminate Them with IPM
Mealybugs are sap-sucking pests that colonize internodes, leaf axils, and buds of cannabis plants, producing honeydew, sooty mold, and a direct pathway to Botrytis. Control requires strict quarantine, natural enemies, and potassium soap; synthetic chemicals are a last resort and are contraindicated during flowering.
Read guide →