Home Grow System Equipment Learn Troubleshooting Blog Gallery About
Visual library

Troubleshooting: the complete image library

Spot it, name it, fix it — visual diagnosis for sick plants and post-harvest problems. Every image below is a real teaching asset from the troubleshooting guides — grouped by topic, captioned, and linked to the article it lives on. Click any image to view it full size.

Early calcium deficiency on young upper cannabis growth: small irregular brown and tan spots with faint leaf distortion.
Nutrient & pH symptoms Early Calcium Deficiency Used on cannabis nutrient deficiencies
Moderate calcium deficiency: coalescing brown spots and crinkled, twisted new-growth margins on a young cannabis leaf beside a healthy older leaf.
Nutrient & pH symptoms Moderate Calcium Deficiency Used on cannabis nutrient deficiencies
Severe calcium deficiency: brown, necrotic, hooked and distorted new growth at a cannabis growing tip.
Nutrient & pH symptoms Severe Calcium Deficiency Used on cannabis nutrient deficiencies
Early iron deficiency on cannabis new growth: bright pale-yellow interveinal chlorosis on the youngest upper leaves with sharp green veins.
Nutrient & pH symptoms Early Iron Deficiency Used on cannabis nutrient deficiencies
Moderate iron deficiency: near-white lemon-yellow new growth on cannabis with faint green veins, older leaves still green.
Nutrient & pH symptoms Moderate Iron Deficiency Used on cannabis nutrient deficiencies
Early magnesium deficiency on a lower cannabis fan leaf: yellowing between the veins while the vein network stays green (interveinal chlorosis).
Nutrient & pH symptoms Early Magnesium Deficiency Used on cannabis nutrient deficiencies
Moderate magnesium deficiency: pronounced interveinal yellowing on a lower cannabis fan leaf, the green vein skeleton still legible, with the first rust flecks appearing between the veins.
Nutrient & pH symptoms Moderate Magnesium Deficiency Used on cannabis nutrient deficiencies
Severe magnesium deficiency: rusty orange-brown necrotic blotches spreading between the veins of a lower cannabis leaf, the outer veins beginning to yellow.
Nutrient & pH symptoms Severe Magnesium Deficiency Used on cannabis nutrient deficiencies
Early-stage nitrogen deficiency on a cannabis plant: the lowest, oldest fan leaves just beginning to pale and yellow.
Nutrient & pH symptoms Early Nitrogen Deficiency Used on cannabis nutrient deficiencies
Nitrogen-deficient cannabis fan leaf yellowing from the bottom of the plant upward, the classic sign of low nitrogen.
Nutrient & pH symptoms Nitrogen Deficiency Cannabis Leaf Used on beginner mistakes small space grows
Moderate nitrogen deficiency: lower cannabis fan leaves turning solid yellow and the fade climbing up the plant.
Nutrient & pH symptoms Moderate Nitrogen Deficiency Used on cannabis nutrient deficiencies
Severe nitrogen deficiency: lower cannabis leaves yellowed, browning, and dying off while the fade pushes high up the plant.
Nutrient & pH symptoms Severe Nitrogen Deficiency Used on cannabis nutrient deficiencies
Nitrogen toxicity on cannabis: very dark glossy emerald leaves with tips hooked sharply downward into a claw.
Nutrient & pH symptoms Nitrogen Toxicity (the Claw) Used on cannabis nutrient deficiencies
Early nutrient burn on a cannabis leaf: a healthy deep-green leaf with only the very tips of the leaflets turning crisp tan-brown.
Nutrient & pH symptoms Early Nutrient Burn Used on cannabis nutrient deficiencies
Severe nutrient burn on a cannabis leaf: deep green interior with crisp brown burn spreading from the tips back along the margins, slight clawing.
Nutrient & pH symptoms Severe Nutrient Burn Used on cannabis nutrient deficiencies
Cannabis nutrient deficiency chart mapping leaf symptoms — yellowing, spotting, and discoloration — to nitrogen, magnesium, calcium, and potassium causes.
Nutrient & pH symptoms Cannabis Nutrient Deficiency Leaf Chart Used on beginner mistakes small space grows
pH lockout on cannabis: a plant section showing several conflicting deficiency symptoms at once — interveinal yellowing, brown spots, pale new growth, and burnt tips.
Nutrient & pH symptoms pH Lockout Used on cannabis nutrient deficiencies
Early phosphorus deficiency on a lower cannabis fan leaf: unusually dark dull blue-green foliage with a red-purple petiole, the quiet first cue.
Nutrient & pH symptoms Early Phosphorus Deficiency Used on cannabis nutrient deficiencies
Moderate phosphorus deficiency: dark dull blue-green lower cannabis leaf with irregular bronze-purple blotches and a red-purple petiole.
Nutrient & pH symptoms Moderate Phosphorus Deficiency Used on cannabis nutrient deficiencies
Severe phosphorus deficiency: lower cannabis leaf with widespread dark bronze to purple-brown necrotic blotches and a deep red-purple petiole.
Nutrient & pH symptoms Severe Phosphorus Deficiency Used on cannabis nutrient deficiencies
Early potassium deficiency on a lower cannabis fan leaf: yellowing and tan scorch beginning at the leaf margins and tips while the interior stays green.
Nutrient & pH symptoms Early Potassium Deficiency Used on cannabis nutrient deficiencies
Moderate potassium deficiency: brown crispy scorched margins advancing inward with rust flecks near the edges of a lower cannabis leaf.
Nutrient & pH symptoms Moderate Potassium Deficiency Used on cannabis nutrient deficiencies
Severe potassium deficiency: wide brown necrotic burnt margins scorched inward, the leaf interior the last green tissue.
Nutrient & pH symptoms Severe Potassium Deficiency Used on cannabis nutrient deficiencies
Phosphorus deficiency purpling on cannabis: deep red-purple stems and petioles with attached lower leaves that are dark, dull and sluggish blue-green with a faint bronze cast.
Nutrient & pH symptoms Purple Stems — Phosphorus Used on cannabis nutrient deficiencies
Sulfur deficiency on cannabis: uniformly pale yellow-green new growth including the veins, no green vein network, older leaves greener.
Nutrient & pH symptoms Sulfur Deficiency Used on cannabis nutrient deficiencies
Cold-stress purpling on cannabis: purple and red flushing across the leaf blades and petioles of an otherwise vigorous, healthy plant with firm, full leaves.
Light, heat & water stress Cold-Stress Purpling Used on index
Severe heat stress on cannabis: pronounced upward leaf cupping with dry, crisping brown margins concentrated at the hottest top canopy, with slight bleaching near the lamp.
Light, heat & water stress Severe Heat Stress Used on index
Early heat stress on cannabis: upper-canopy fan leaves cupping upward into a taco shape with the tips pointing up, the leaves still green.
Light, heat & water stress Early Heat Stress (Taco Leaf) Used on index
Early light burn on cannabis: only the topmost leaves nearest the lamp are pale yellow-white, with a sharp gradient to healthy green just below.
Light, heat & water stress Early Light Burn (Bleached Tops) Used on index
Moderate light burn on cannabis: persistent pale bleached top leaves that resist greening, with leaf tips beginning to crisp brown at the canopy peak while the lower canopy stays green.
Light, heat & water stress Moderate Light Burn Used on index
Severe light burn on cannabis: the top cola and surrounding leaves bleached near white-cream and crisped, with a sharp boundary to normal green just below.
Light, heat & water stress Severe Light Burn Used on index
Comparison of an overwatered cannabis plant with drooping, curled-down leaves beside an underwatered plant with thin, wilting leaves.
Light, heat & water stress Overwatered vs Underwatered Cannabis Used on why growth is slow in a compact setup
Overwatered cannabis in a plain nursery pot: leaves drooping downward but firm, full, dark green and heavy, folding down from the petiole over wet media.
Light, heat & water stress Overwatering Droop Used on index
Cold-stress purpling on cannabis stems: red-purple stems and petioles on an otherwise vigorous, healthy plant with vivid green, firm leaves — the purpling is the only abnormality.
Light, heat & water stress Purple Stems — Cold Used on index
Underwatered cannabis in a plain nursery pot: leaves thin, limp, papery and lifeless, hanging weakly, with dry media pulled from the pot edges.
Light, heat & water stress Underwatering Wilt Used on index
Wind burn on cannabis: only the leaves sitting in a fan’s airflow path are clawing, twisting and slightly tattered, while leaves outside the airflow stay normal.
Light, heat & water stress Wind Burn Used on index
DWC algae contamination: bright green slimy algal film coating the light-exposed net-pot rim and reservoir walls, while roots dipping below the water may still be white.
Root & reservoir problems DWC Algae Contamination Used on root problems in dwc
Comparison of healthy white cannabis feeder roots versus fungus-gnat-damaged roots — fine white roots severed and stripped with larvae present, not brown or slimy.
Root & reservoir problems Fungus Gnat Root Damage vs Healthy Used on index
Healthy cannabis roots in DWC: a brilliant white, fibrous, abundant root mass in clean clear water with no tint, slime, or browning anywhere.
Root & reservoir problems Healthy White Roots (Reference) Used on root problems in dwc
Reservoir biofilm on cannabis roots: a tan-to-brown slippery biofilm coating the roots and reservoir walls while the roots stay mostly intact and structured — the pre-rot stage.
Root & reservoir problems Reservoir Biofilm Slime Used on root problems in dwc
Root aphids on cannabis: small soft-bodied insects on the roots and media surface with telltale white waxy specks, the root zone stressed and declining.
Root & reservoir problems Root Aphid Damage Used on root problems in dwc
Early root rot in a DWC reservoir: cannabis roots showing the first off-white to tan discoloration against still-healthy white roots.
Root & reservoir problems Early Root Rot Used on root problems in dwc
Moderate root rot: cannabis roots turning brown and slimy through much of the root mass in a DWC reservoir.
Root & reservoir problems Moderate Root Rot Used on root problems in dwc
Severe root rot: cannabis roots collapsed into brown, slimy strands with widespread decay in the reservoir.
Root & reservoir problems Severe Root Rot Used on root problems in dwc
Comparison of harmless nutrient or pH staining on cannabis roots versus true brown, slimy root rot.
Root & reservoir problems Root Rot vs Brown Staining Used on root problems in dwc
Side-by-side comparison of healthy white cannabis roots versus brown, slimy root rot in a DWC reservoir.
Root & reservoir problems Root Rot vs Healthy Roots Used on root problems in dwc
A dense colony of pear-shaped aphids clustered on a cannabis stem and leaf underside, with cast skins and sticky honeydew.
Pests, mold & mildew Aphid Colony Used on index
Early bud rot on a living cannabis plant: a single brown, wilted flag leaf mid-cola with a hint of grey mould at its base, on an otherwise healthy green cola still on the standing plant.
Pests, mold & mildew Botrytis on a Living Cola (Flag Leaf) Used on bud rot and mold
Early bud rot inside a cannabis cola: the first grey-brown fuzz and a single wilted leaf deep in the bud.
Pests, mold & mildew Early Bud Rot Used on bud rot and mold
A cannabis cola broken open to reveal grey-brown bud rot decaying the bud from the inside out.
Pests, mold & mildew Bud Rot Inside a Cannabis Cola Used on beginner mistakes small space grows
Moderate bud rot: grey-brown rot hollowing out a noticeable section of a cannabis cola from the inside.
Pests, mold & mildew Moderate Bud Rot Used on bud rot and mold
Severe bud rot: a cannabis cola largely consumed by grey-brown, dusty botrytis decay.
Pests, mold & mildew Severe Bud Rot Used on bud rot and mold
Comparison of a healthy dense cannabis cola beside one infected with grey-brown bud rot.
Pests, mold & mildew Bud Rot vs Healthy Cola Used on bud rot and mold
Fungus gnat larvae in the top layer of moist cannabis grow media: small translucent larvae with shiny black heads.
Pests, mold & mildew Fungus Gnat Larvae in Media Used on index
Powdery mildew on a cannabis bud: a flat, matte, flour-white powdery coating dusting the calyxes and sugar leaves of the flower itself, dull and cakey rather than glassy resin.
Pests, mold & mildew Powdery Mildew on the Bud Used on bud rot and mold
Early powdery mildew: the first faint white powdery spots appearing on a cannabis fan leaf.
Pests, mold & mildew Early Powdery Mildew Used on bud rot and mold
White, dusty powdery mildew spreading across the surface of a cannabis fan leaf.
Pests, mold & mildew Powdery Mildew on a Cannabis Leaf Used on beginner mistakes small space grows
Moderate powdery mildew: white powdery patches spreading across several cannabis fan leaves.
Pests, mold & mildew Moderate Powdery Mildew Used on bud rot and mold
Severe powdery mildew: cannabis leaves and bud sites coated in a white powdery fungus.
Pests, mold & mildew Severe Powdery Mildew Used on bud rot and mold
Split-screen macro at identical scale: left, powdery mildew as a flat matte dusty white film on the cannabis leaf surface; right, trichomes as glassy translucent dome-tipped glands on clear stalks standing up off the surface.
Pests, mold & mildew Powdery Mildew vs Trichome Frost Used on bud rot and mold
Russet mite damage on cannabis top growth: curled, glossy, drooping new leaves with bronzed petioles and no visible insect.
Pests, mold & mildew Russet Mite Damage Used on index
Septoria leaf spot on a lower cannabis fan leaf: numerous discrete round brown spots each ringed by a bright yellow halo, several with tiny dark fungal specks at their centres, scattered across the blade.
Pests, mold & mildew Septoria Leaf Spot Used on cannabis nutrient deficiencies
Moderate spider-mite infestation on cannabis: bronzed, stippled leaf tissue with the first fine silk webbing appearing at the petiole junctions.
Pests, mold & mildew Moderate Spider Mite Infestation Used on index
Severe spider-mite infestation: dense fine webbing blanketing a cannabis bud and leaves, with visible mites and debris caught in the silk.
Pests, mold & mildew Severe Spider Mite Webbing Used on index
Early spider-mite damage: hundreds of tiny pale pinprick stippling dots scattered across the upper surface of a cannabis fan leaf, no webbing yet.
Pests, mold & mildew Early Spider Mite Stippling Used on index
Extreme macro of the underside of a cannabis leaf: a colony of two-spotted spider mites with translucent eggs and fine silk along the midrib.
Pests, mold & mildew Spider Mite Underside Colony Used on index
Early thrips damage on a cannabis fan leaf: silvery-bronze glossy feeding scars flecked with tiny black frass specks, distinct from mite stippling dots.
Pests, mold & mildew Thrips Feeding Scars (Early) Used on index
Moderate thrips damage on cannabis: merged silver-bronze scarred zones across the leaf blade with scattered black frass, the leaf beginning to distort and yellow.
Pests, mold & mildew Thrips Damage (Moderate) Used on index
Severe thrips damage on cannabis: extensive silver-grey papery scarring over most of the leaf, dry, distorted and curling, with browning margins — not clean light-burn bleaching.
Pests, mold & mildew Thrips Damage (Severe) Used on index
Tiny white moth-like whiteflies and flat oval nymphs on the underside of a cannabis leaf.
Pests, mold & mildew Whitefly on Leaf Underside Used on index
Differential board for brown spots on cannabis leaves: calcium (new growth), potassium (margins), phosphorus (old leaves), leaf septoria (round haloed spots), and thrips (silver scars) — feeding problem versus bug or fungus.
Diagnosis & decision tools Brown Spots — Causes Compared Used on cannabis nutrient deficiencies
Cannabis nutrient deficiency mobility board: old/lower-leaf-first mobile nutrients (nitrogen, magnesium, potassium, phosphorus) versus new/upper-growth-first immobile nutrients (calcium, iron, sulfur).
Diagnosis & decision tools Mobile vs Immobile Deficiency Board Used on cannabis nutrient deficiencies
Differential board for a drooping cannabis plant by texture and media: overwatering (firm, full, wet), underwatering (thin, papery, dry), heat (upward taco curl), and root rot (whole-plant droop from slimy roots).
Diagnosis & decision tools Drooping — Causes Compared Used on index
Comparison board: left, fungal leaf spot with round brown spots and yellow halos on a lower cannabis leaf; right, calcium deficiency with irregular spots and twisting on new upper growth.
Diagnosis & decision tools Leaf Spot vs Calcium Deficiency Used on cannabis nutrient deficiencies
Comparison board: left panel light burn with bleached pale top leaves nearest the lamp, right panel nutrient burn with a deep-green leaf whose tips are burnt brown.
Diagnosis & decision tools Light Burn vs Nutrient Burn Used on index
Cannabis pest damage identification board comparing spider-mite stippling, thrips silver scarring, fungus-gnat larvae, aphids, and whiteflies by their damage signatures.
Diagnosis & decision tools Pest Damage ID Board Used on index
Cannabis nutrient availability chart by root-zone pH from 5.0 to 8.0, showing which nutrients lock out at which pH, with hydro/coco and soil target zones.
Diagnosis & decision tools Cannabis Nutrient Availability by pH Used on cannabis nutrient deficiencies
Cannabis diagnosis decision board: start from what stands out first — leaves changing colour, leaves drooping, or spots, powder or bugs — each routing through a visible cue to the right problem family.
Diagnosis & decision tools Cannabis Plant-Problem Triage Used on index
Three-panel comparison of cannabis purple stems: genetics (harmless, lush green leaves), phosphorus deficiency (dark dull sluggish leaves), and cold nights (healthy green leaves) — the leaf state decides.
Diagnosis & decision tools Purple Stems — Genetic vs Deficiency Used on index
Differential board for yellowing cannabis leaves grouped by where it starts: nitrogen and magnesium (old lower leaves), iron (new upper growth), and overwatering, root rot and pH lockout (root-zone).
Diagnosis & decision tools Yellow Leaves — Causes Compared Used on cannabis nutrient deficiencies