The most common questions customers ask in our grow store — answered by our expert staff with 10+ years of commercial growing experience. From troubleshooting deficiencies to maximizing yields.
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Yellow leaves are most commonly caused by nitrogen deficiency, overwatering, or pH lockout. Location matters: lower leaves = normal aging or N deficiency; upper leaves = pH issues or micronutrient lockout; widespread = overwatering or root problems.
1. Nitrogen Deficiency (Most Common)
2. Overwatering
3. pH Lockout
4. Light Burn
Always check pH first before adding more nutrients. 80% of "deficiencies" are actually pH lockout. Also check leaf position: bottom = deficiency, top = toxicity or lockout.
For beginners in soil: Fox Farm Trio (simple, proven). For coco/hydro: General Hydroponics Flora Series (3-part, forgiving). For "set it and forget it": Jack's 3-2-1 (dry, cheap, professional). All three are carried at Toledo and come with proven feeding schedules.
1. Fox Farm Trio (Grow Big, Big Bloom, Tiger Bloom)
2. General Hydroponics Flora Series (FloraGro, FloraMicro, FloraBloom)
3. Jack's 3-2-1 (Professional Fertilizer)
Honorable Mentions:
Start at 50% of the recommended feed strength for your first grow. It's easier to add more nutrients than to fix nutrient burn. Also: follow a proven feeding chart religiously — don't "wing it" your first time.
There's no universal schedule — it depends on container size, medium, plant size, temperature, and humidity. General rule: water when the top 1-2 inches of soil is dry. In soil: every 2-3 days. In coco: daily to twice daily. In hydro: constant reservoir or automated drip.
Soil
Coco Coir
Hydro (DWC, NFT, Ebb & Flow)
Factors That Change Watering Frequency
In soil: water in the morning so plants have all day to use it. In coco: multiple small feedings per day > one big feeding. And always check VPD — if humidity is off, your watering schedule won't matter.
For LED: 30-40 watts per square foot. For coverage: a 2x2' space needs ~150W LED, 3x3' needs 300-350W, 4x4' needs 480-600W, 5x5' needs 750W+. More important than watts: target 600-900 PPFD in veg, 900-1200 PPFD in bloom.
| Tent/Space Size | Recommended Wattage | Example Lights (at Toledo) |
|---|---|---|
| 2x2' (4 sq ft) | 120-160W | AC Infinity IONFRAME EVO4, HLG 100 |
| 2x4' (8 sq ft) | 240-320W | AC Infinity IONBOARD S24, Growers Choice ROI-E200 |
| 3x3' (9 sq ft) | 270-360W | AC Infinity IONBOARD S33, HLG 300 |
| 4x4' (16 sq ft) | 480-640W | Gavita 1700e, AC Infinity IONBOARD S44, HLG 550 |
| 5x5' (25 sq ft) | 750-1000W | Gavita 1930e, Growers Choice ROI-E720 |
| 4x8' (32 sq ft) | 960-1280W | 2x Gavita 1700e, 2x AC Infinity IONBOARD S44 |
PPFD Targets (More Important Than Watts)
Common Mistakes
Invest in a PAR meter or use a phone app (Photone is decent). Measure PPFD at canopy level and adjust light height until you hit target numbers. More light ≠ better; too much light causes stress and bleaching.
There's no "best" — it depends on your experience level and grow style. Soil = easiest/most forgiving. Coco coir = faster growth, more control. Hydro (DWC/NFT) = fastest growth but least forgiving. Rockwool = commercial-grade, requires precision.
1. SOIL (Potting Mix)
2. COCO COIR (Coconut Fiber)
3. ROCKWOOL (Stone Wool)
4. HYDROPONICS (DWC, NFT, Aeroponics)
5. SOILLESS MIX (Peat/Perlite Blend)
Start with soil for your first grow. Once you nail the basics (environment, nutrients, harvest timing), graduate to coco for faster growth. Hydro is for growers who've already done 2-3 successful grows.
Burned leaf tips are usually caused by nutrient burn (too much fertilizer) or light stress (light too close). Check: Is it all over the plant? = nutrient burn. Only at the very top? = light burn.
1. Nutrient Burn (Most Common)
2. Light Burn / Light Stress
How to Tell the Difference
| Symptom | Nutrient Burn | Light Burn |
|---|---|---|
| Location | All over plant (top to bottom) | ONLY top canopy |
| Color | Brown/yellow tips | White/bleached tips |
| Leaf Shape | Tips curl down ("clawing") | Leaves taco/curl upward |
| EC/PPM | High (2.0+ veg, 2.5+ bloom) | Normal range |
Other Causes (Less Common)
Slight tip burn (<5% of leaf tips) is actually optimal — it means you're feeding at the upper limit without going over. Many commercial growers aim for this. But if it's spreading or worsening, back off immediately.
Hydro/Coco: 5.8-6.2 (sweet spot: 5.9-6.0). Soil: 6.0-6.8 (sweet spot: 6.3-6.5). pH controls nutrient availability — wrong pH = lockout (even with perfect nutrients).
| Medium | pH Range | Optimal pH |
|---|---|---|
| Hydro (DWC, NFT) | 5.5-6.0 | 5.8 |
| Coco Coir | 5.8-6.2 | 5.9-6.0 |
| Rockwool | 5.5-6.0 | 5.7-5.8 |
| Soil (Organic) | 6.0-7.0 | 6.3-6.5 |
| Soilless Mix (Peat/Perlite) | 5.8-6.3 | 6.0-6.2 |
Why pH Matters
pH controls nutrient availability. Each nutrient is absorbed best at specific pH ranges. If pH is off, nutrients become "locked out" (they're in the medium but plants can't absorb them).
Nutrient Availability by pH
pH Drift Strategy
Some growers "pH drift" intentionally: alternate feedings between 5.8 → 6.0 → 6.2 to ensure all nutrients are available at some point. This mimics natural soil buffering.
How to Adjust pH
Common pH Problems
Calibrate your pH meter every 1-2 weeks. A meter that's off by 0.5 pH can cause massive nutrient lockout. Also: always pH AFTER adding nutrients (nutrients change pH significantly).
Spider mites require aggressive IPM (Integrated Pest Management). Spray every 3 days for 2 weeks minimum. Use: Lost Coast Plant Therapy, Doctor Zymes, or Sierra Natural Science 217 (SNS-217). Rotate products to prevent resistance. In flower: only use organic sprays.
Step 1: Confirm Spider Mites
Step 2: Immediate Action (First 24 Hours)
Step 3: Treatment Schedule (2-3 Weeks)
Spray every 3 days (kills newly hatched mites before they mature). Rotate products every spray to prevent resistance:
Step 4: Prevention (Ongoing)
Flower-Safe Options
If mites appear in late flower (< 3 weeks from harvest), only use organic foliar sprays:
Avoid in flower: Synthetic pyrethrins, anything with systemic action
Nuclear Option (Severe Infestations)
If infestation is out of control in veg:
Prevention is 100x easier than treatment. Spray Lost Coast Plant Therapy once per week in veg as preventive measure. Also: quarantine ANY new clones/plants for 2 weeks — 90% of infestations come from outside sources.
Flip when plants are 50-60% of final desired height (they'll double in size during stretch). Typical: 12-18" tall for indica-dominant, 8-12" for sativa-dominant. Also consider: tent space, root development, and whether you topped/trained.
Plant Size: Most strains double (indica) to triple (sativa) in height during 2-3 week "stretch" after flip. Leave headroom for lights.
Genetics: Indica = shorter, bushier, 1.5-2x stretch. Sativa = taller, lankier, 2-3x stretch. Hybrids vary.
Training: If you topped/LST'd, flip sooner (bushier canopy). If not, give more veg time for structure.
Root Development: Wait until roots fill pot (white roots visible at drainage holes). Underdeveloped roots = smaller yields.
Typical Timeline: 4-6 weeks veg from clone, 6-8 weeks from seed (photoperiod strains).
Flip earlier than you think. New growers always veg too long and run out of vertical space. Better to flip early and get smaller plants than have colas touching your lights.
Stretching = not enough light (plants reach toward light source), too much heat (elongation response), or genetics (some strains are naturally tall). Fix: increase light intensity or move light closer, lower temps to 75-78°F.
Cause #1: Insufficient Light — Plants stretch to get closer to weak light. Solution: Add more light, lower light 6-12", or increase dimmer setting.
Cause #2: Heat Stress — High temps (85°F+) trigger elongation. Solution: Lower temps to 75-80°F, increase airflow, add AC.
Cause #3: Genetics — Sativa-dominant strains naturally stretch. Solution: Choose indica genetics, or train with LST/SCROG.
Prevention: Keep light 12-24" from seedlings (adjust based on intensity), maintain 75-80°F temps, use oscillating fans for airflow.
That's powdery mildew (PM) — a fungus that thrives in high humidity (60%+) with poor airflow. Spray immediately with: Lost Coast Plant Therapy, GreenCure (potassium bicarbonate), or diluted H2O2 (1:9 ratio). Lower humidity below 50%, increase airflow.
Immediate Treatment: Spray all affected leaves with anti-fungal (GreenCure, Lost Coast, or 1 part H2O2 + 9 parts water). Remove heavily infected leaves.
Environmental Fix: Lower humidity to 40-50%, add dehumidifier, increase airflow with fans, space plants further apart.
Prevention: Keep RH below 50% in flower, prune lower fan leaves (improves airflow), spray sulfur burner in veg (do NOT use in flower).
Biggest yield factors (in order): 1) Light intensity (aim 900-1200 PPFD in flower), 2) Genetics (choose high-yielding strains), 3) Environment (dial in VPD/temps), 4) Training (SCROG/LST for even canopy), 5) Nutrients (proper feeding + PK boost in bloom).
1. Light = Yield — More quality light = more yield. Target 40-50W LED per sq ft. Add CO2 to push to 1500 PPFD.
2. Genetics Matter — Some strains yield 2x others. Choose proven high-yielders (Blue Dream, GG#4, OG Kush, Wedding Cake).
3. Perfect Environment — Dial in VPD (1.0-1.2 veg, 1.2-1.5 bloom), keep temps 75-82°F, RH 40-50% in flower.
4. Training Techniques — SCROG (Screen of Green), LST (Low Stress Training), topping/FIM — create flat, even canopy.
5. Nutrition — Feed to upper EC limits (without burn), add PK boost weeks 3-6 of flower (Terpinator, Big Bud, Overdrive).
6. Longer Veg — Bigger plant in veg = bigger yield in flower (within tent limits).
7. CO2 Enrichment — 1200-1500 ppm CO2 + high light = 20-30% yield increase (sealed room only).
Upgrade lights before anything else. Going from cheap LED to quality Gavita/HLG can double your yield overnight. Environment is second — fix VPD and you'll see 20%+ gains immediately.
VPD (Vapor Pressure Deficit) = the relationship between temperature and humidity that drives transpiration (how plants breathe/drink). Target VPD: 0.8-1.0 kPa (seedling), 1.0-1.2 kPa (veg), 1.2-1.5 kPa (flower). Get it right = explosive growth, wrong = stunted plants.
Why VPD Matters: VPD controls how fast plants transpire (pull water from roots → out of leaves). Proper VPD = perfect nutrient uptake + CO2 absorption.
Too Low VPD (high humidity, cool temps) = slow transpiration, weak nutrient uptake, mold risk.
Too High VPD (low humidity, hot temps) = excessive transpiration, stress, burned tips, stunted growth.
How to Hit Target VPD: Use VPD chart (Google "VPD chart cannabis"). Adjust temp/humidity together. Example: 78°F + 60% RH = 1.2 kPa (perfect for flower).
Tools: Inkbird humidity controller + humidifier/dehumidifier. TrolMaster environmental controller (automates everything).
Soil = easier, more forgiving, slower growth. Coco = faster growth (20-30%), more control, requires daily watering + runoff. First grow? Use soil. Want maximum yield? Use coco.
Soil Pros: Forgiving (buffers pH/nutrients), water every 2-4 days, can be organic, reusable.
Soil Cons: Slower growth, heavier, risk of pests (fungus gnats).
Coco Pros: Faster growth, more control over feeding, no pests, better aeration.
Coco Cons: Requires daily watering, must add cal-mag, not forgiving (pH/EC must be dialed in).
Recommendation: Beginners → soil (Fox Farm Ocean Forest). Intermediate → coco (Grow Junky, Mother Earth).
Cut 4-6" branch at 45° angle, dip in rooting gel (Clonex), place in rockwool/rapid rooter, keep under dome with high humidity (80-90%), mist daily. Roots appear in 7-14 days. Lights: 18-24 hours, low intensity (200-400 PPFD).
Step-by-step:
Switch to bloom formula (high P-K ratio) at flip. Add PK booster weeks 3-6 (Terpinator, Big Bud, Overdrive). Continue cal-mag throughout. Late flower (week 7+): reduce nitrogen, increase P-K for density + terpenes.
Base Bloom Nutrients: Fox Farm Tiger Bloom, GH FloraBloom, Athena Bloom — switch at flip to 12/12.
PK Boosters (Weeks 3-6): Big Bud, Overdrive, Terpinator, Rock Resinator — increases flower density + resin.
Cal-Mag (Throughout): Botanicare Cal-Mag Plus — especially important in coco/hydro.
Ripening (Week 7+): Heavy 16 Finish, Advanced Nutrients Overdrive — finish strong, increase terpenes.
Flush (Final Week): Plain pH'd water or FloraKleen — remove excess salts for clean finish.
Airy buds = not enough light (most common), high temps (85°F+), genetics (some strains don't stack tight), or poor nutrition (low P-K in flower). Fix: increase light intensity to 900-1200 PPFD, keep temps 75-80°F, add PK booster.
Cause #1: Insufficient Light — Buds need 900-1200 PPFD to develop density. Solution: upgrade lights or add more wattage.
Cause #2: High Temps — 85°F+ = airy, leafy buds. Solution: keep flower temps 75-80°F.
Cause #3: Genetics — Sativa-dominant strains naturally produce airier buds. Solution: choose indica genetics.
Cause #4: Low P-K — Not enough phosphorus/potassium in bloom. Solution: increase bloom nutrients, add PK booster.
Cause #5: Harvesting Too Early — Buds bulk up final 2 weeks. Solution: wait for proper trichome color (cloudy/amber).
Target 40-50% RH in flower (lower in late flower to prevent mold). Use dehumidifier (Quest Dual 110, Anden 130), increase airflow with fans, prune lower fan leaves, and increase exhaust fan speed. Sealed room? AC also removes moisture.
Ideal Flower RH: 50-55% (weeks 1-4), 45-50% (weeks 5-6), 40-45% (weeks 7-9+). Lower RH = less mold risk + better terpenes.
Tools: Quest Dual 110 (4x4'-5x5'), Anden 130 (larger rooms), AC Infinity controller + dehumidifier.
Other Tips: Defoliate (remove blocking fan leaves), space plants apart, seal tent (prevent outside humidity), run lights at night (when outdoor humidity is lower).
Drying: Hang whole plant or branches in dark room at 60°F / 60% RH for 7-14 days (until stems snap, not bend). Curing: Trim, place in jars, burp daily for 2 weeks, then weekly for 1-2 months. Proper cure = better taste, smoother smoke, stronger effects.
Drying (7-14 days): Hang upside-down in dark room, 60°F / 60% RH, gentle airflow (not directly on buds). Check daily — done when small stems snap (not bend).
Curing (2-8 weeks): Trim dry buds, place in glass jars (fill 75%), seal with lid. Burp jars 10-15 min daily for first 2 weeks (release moisture). Then burp weekly for 1-2 months. Add Boveda 62% packs to maintain humidity.
Why Cure? Breaks down chlorophyll (harsh taste), converts cannabinoids (stronger), enhances terpenes (better smell/flavor).
Check trichomes (resin glands) with 60x+ magnifier. Harvest when: 70-90% cloudy/milky (peak THC, uplifting high) OR 20-30% amber (more relaxing, couch-lock effect). Ignore pistils — they're unreliable. Breeder's timeline is a guideline, not gospel.
| Trichome Color | Maturity | Effect |
|---|---|---|
| Clear/Transparent | Too early | Low potency, racy/anxious high |
| Cloudy/Milky (70-90%) | Peak THC | Energetic, uplifting, creative high |
| Amber (10-20%) | Balanced | Balanced high (head + body) |
| Amber (30%+) | CBN forming | Sedative, couch-lock, sleepy |
Where to Check Trichomes
Harvest Windows by Desired Effect
Other Harvest Indicators (Less Reliable)
Common Mistakes
When in doubt, wait another week. It's almost impossible to harvest too late (within reason), but harvesting too early loses 20-30% potency and ruins the taste. Patience pays off.
Our team of expert growers is here to help — no question is too basic or too advanced
Visit our Toledo store, call our expert staff, or chat with us online. We're here to help you grow!