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Contamination Prevention Guide

Complete guide for contamination prevention — step-by-step workflow, tools, checklist, and expert tips to get started.

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Workflow

Establish Sterile Protocol
30 minutes
Define sterile technique steps, workspace setup, and contamination response procedures.
Hydroponic Water Change Interval
Calculate Contamination Threshold
45 minutes
Set acceptable contamination rate targets and identify cleaning frequency for workspaces.
Hydroponic Water Change Interval Nutrient Solution EC Calculator
Set Up Clean Workspace
2-4 hours
Install still air box or HEPA flow, stock 70% isopropyl, and establish washdown sanitation schedule.
Hydroponic Water Change Interval Nutrient Solution EC Calculator Grow Tent Ventilation CFM
Monitor and Respond
1 hour
Inspect all batches daily, identify contamination by color, and execute quarantine or disposal protocol.
Nutrient Solution EC Calculator Clone Humidity Dome Sizing

Tools Used

Checklist

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Planning

Write sterile technique protocol for all inoculation workCritical

Preparation

Stock 70% isopropyl and 10% bleach sanitizing solutionsCritical

Hardware

Set up HEPA flow hood or still air box for inoculationCritical

Execution

Quarantine new batches 7 days before grow room introductionCritical
Inspect all active batches daily for contamination colorsCritical

Safety

Define outdoor disposal procedure for contaminated materialCritical

Documentation

Log contamination events and identify root causeCritical

Quality

Track batch failure rate — investigate if above 5%Critical

Reference Materials

Contamination IDTable

Key benchmarks for contamination prevention.

Color	Likely	Action
Green	Trichoderma	Remove immediately
Black	Aspergillus	Remove + review sterile tech
Orange	Nematodes	Discard all + sanitize

Sterile TechniqueFormula

Flame loop, 70% ISO spray, HEPA — reduce inoculation time

QuarantineStandard

Isolate new batches 7 days before introducing to grow room.

Speed Matters
Every second open jar exposure to room air increases contamination risk — prepare everything before opening.
Green Means Remove
Trichoderma spreads fast through air — remove green-contaminated blocks immediately, do not inspect further indoors.
DIY Still Air Box
A clear plastic tub with arm holes costs $15 and reduces contamination dramatically vs open bench work.

Safety Notes

Aspergillus and other mold contaminants produce harmful spores — wear N95 mask and dispose of contaminated material outdoors.
Never consume mushrooms from any batch that showed contamination, even from apparently clean areas of the same block.

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Contamination Prevention Guide

Workflow

Establish Sterile Protocol

Calculate Contamination Threshold

Set Up Clean Workspace

Monitor and Respond