🍄 Monotub Growing Guide

• Method: Bulk substrate in monotub fruiting chamber
• Difficulty: Intermediate (requires sterile technique)
• Timeline: 6-8 weeks from spawn to first harvest
• Yield: 1-4 ounces per flush, 4-6 flushes typical
• Cost: $100-200 for initial setup
• Space: One 54-66 quart tub per grow
• Best For: Experienced growers wanting high yields

Monotub Construction

• Clear plastic tub: 54-66 quart with lid (Sterilite, Rubbermaid)
• Drill with hole saw: 2" or 2.5" hole saw bit
• Polyfill: For stuffing holes (or micropore tape)
• Black trash bags: Or black spray paint for sides (optional)

Spawn Production

• Grain jars/bags: 3-5 quarts colonized grain spawn
  • Brown rice, rye berries, popcorn, or millet
  • Can use Uncle Ben's bags (easier)
  • Or make your own grain spawn
• Spore syringe or culture: For inoculating grain

Bulk Substrate Ingredients

• Coco coir: 650g brick (makes ~8-9 quarts hydrated)
• Vermiculite: 2 quarts
• Gypsum: 1 cup (optional, adds calcium)
• Water: 4 quarts (for hydration)

Tools & Supplies

• Large bucket with lid (5-gallon)
• Thermometer
• Gloves & face mask
• 70% isopropyl alcohol
• Large mixing tub or liner

Drilling Holes for FAE (Fresh Air Exchange)

1. Mark hole positions:
   • 4-6 holes per long side (spaced 4-6" apart)
   • 2-3 holes per short side
   • Position 2-3" from bottom edge
   • Total: 12-18 holes around tub
2. Drill 2" holes at marked positions
3. Stuff with polyfill
   • Fill each hole loosely
   • Should allow air exchange but filter contaminants
   • Don't pack too tight
4. Optional: Liner
   • Black trash bag on sides/bottom
   • Prevents side pins
   • Shrinks with substrate

CVG Recipe (Coco Coir, Vermiculite, Gypsum)

This is "bucket tek" - pasteurization method

Instructions:

1. Heat 4 quarts water to boiling
2. In 5-gallon bucket, add:
   • 650g coco coir brick (broken up)
   • 2 quarts vermiculite
   • 1 cup gypsum (optional)
3. Pour boiling water over ingredients
4. Stir thoroughly to distribute heat
5. Close bucket lid tightly
6. Wait 60-90 minutes (pasteurization occurs)
7. Let cool to room temperature (4-8 hours or overnight)
8. Check moisture level:
   • Squeeze handful - should drip 1-3 drops
   • If too wet: spread out to dry slightly
   • If too dry: add small amounts of water

Spawn to Substrate Ratio

Mixing Process

1. Clean workspace
   • Wipe everything with alcohol
   • Wear gloves and mask
   • Work quickly but carefully
2. Break up grain spawn
   • Shake jars/bags to loosen
   • Pour into mixing container
   • Break apart any clumps
3. Add substrate
   • Layer method: spawn, substrate, spawn, substrate
   • Or mix all together
4. Mix thoroughly but gently
   • Even distribution critical
   • Don't compact too much
5. Transfer to monotub
   • Fill to 3-4" depth
   • Level surface gently
   • Don't pack down hard
6. Optional: Casing layer
   • 1/2-1" plain coco coir on top
   • Helps with pinning
   • Not required but helpful
7. Close lid and place in colonization area

Conditions

• Temperature: 75-80°F (24-27°C)
• Lid: Closed (can crack slightly if too much condensation)
• Light: Not needed, dark is fine
• Location: Stable temp area away from direct sunlight

Timeline & What to Expect

• Days 1-3: No visible change
• Days 3-7: Mycelium starts spreading from spawn
• Days 7-14: Rapid colonization, surface turns white
• Days 14-21: Full colonization (100% white surface)

Don't Open During Colonization!

• Opening introduces contamination risk
• Check progress through clear sides only
• Wait for 75-100% colonization before fruiting

Contamination Signs

When to Start Fruiting

• 75-100% colonized surface
• Typically 10-21 days after spawn to bulk
• Don't wait too long (overlay can form)

Initiating Fruiting

1. Introduce fresh air:
   • If modified tub: polyfill allows passive FAE
   • If unmodified: flip lid upside down (creates gap)
   • Or crack lid slightly
2. Provide light:
   • 12 hours light/dark cycle
   • Indirect natural light works
   • Or LED light near tub
3. Lower temperature:
   • 70-75°F (21-24°C) ideal
   • Slight temp drop triggers pinning
4. Maintain humidity:
   • 85-95% relative humidity
   • Look for tiny water droplets on surface
   • Mist sides/lid if too dry

Daily Maintenance

• Modified tub: Minimal - just observe
• Unmodified tub: Fan 1-2x daily if needed
• Misting: Only if surface looks dry
  • Mist walls/lid, not directly on substrate
  • Fine mist only

Pinning Phase (Days 1-7)

• Hyphal knots appear: Small white bumps
• Pins form: Tiny mushroom shapes
• Maintain conditions: Don't change anything!
• Be patient: Can take 3-10 days

Growth Phase (Days 7-14)

• Rapid expansion: Pins grow into mushrooms
• Double size daily: Growth accelerates
• Watch for harvest window: Veils will start breaking

Ideal Conditions

• Temperature: 70-75°F constant
• Humidity: 90-95% (small water droplets visible)
• FAE: Continuous passive or fan 1-2x daily
• Light: 12/12 cycle, indirect

When to Harvest

• Optimal timing: Just as veil breaks (membrane under cap tears)
• Veil still attached but separated from stem
• Before spores drop: Cap fully flattens and releases spores (messy, reduces yield)

Harvesting Technique

1. Wash hands or wear gloves
2. Grasp at base near substrate
3. Twist and pull gently - should come out clean
4. Harvest entire clusters when largest are ready
5. Remove all aborts (small mushrooms that stopped growing)
6. Clean substrate surface gently with hands (remove stumps)

Post-Harvest

• Let substrate rest 5-10 days
• Maintain humidity during rest
• Pins will form for next flush
• Repeat harvest cycle 4-6 times

By Flush

Total Yield Per Tub

• Typical: 4-12 oz dried over all flushes
• Good conditions: 8-16 oz dried
• Excellent conditions: 16-20+ oz dried
• Factors: Genetics, conditions, substrate quality, spawn ratio