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The Ultimate Guide to Spawn to Substrate Monotub Ratios:
For Maximum Mushroom Yield

Monotubs are a popular and efficient method for cultivating mushrooms at home. One of the critical aspects of successful monotub cultivation is getting the ratio of grain to spawn right. In this comprehensive guide, we’ll delve into the ideal monotub ratios of grain to spawn, how to prepare your substrate, and tips for maximising your mushroom yield.

What is a Monotub?

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A monotub generally consists of a large plastic tote or tub with ventilation holes drilled into it. This tub is filled with a mixture of grain spawn and bulk substrate, creating an optimal environment for mycelium growth and mushroom fruiting.

 

At Curious Ape Mushrooms, we offer two types of monotubs:

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  1. Inflatable Monotub

  2. Boom Box Monotub​

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Our monotubs come pre-assembled and include fresh air exchange filters and plugs to maximize control of CO2/O2 levels. They also feature a black bottom to prevent side pinning, redirecting the growth to the top layer mushroom pins for larger, more voluminous yields. Click HERE to view our monotubs.

boom box monotub shrooms
boomer shroomer inflatable monotub

Understanding Grain Spawn to Substrate Ratios

At Curious Ape Mushrooms, we recommend starting with a 1:2 ratio. For each tub (Boom Box or Inflatable Monotub), use 400g of colonized mushroom grain spawn and 800-1000g of substrate.

We sell substrate HERE

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EXAMPLE BELOW: If you use our 1.3KG grain bag and 2.5kg of substrate, you can easily achieve 3 tubs at the 1:2 ratio!

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Common Monotub Ratios

1:1 Ratio (Grain Spawn to Substrate)

  • Pros: Fast colonization, reduced risk of contamination.

  • Cons: Higher spawn requirement, potentially more expensive.

  • Best For: Beginners looking for quick results.

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1:2 Ratio

  • Pros: Balanced approach with efficient colonization and moderate spawn usage.

  • Cons: Slightly slower colonization compared to 1:1.

  • Best For: Intermediate growers seeking a balance between speed and cost.

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1:3 Ratio

  • Pros: Cost-effective, requires less grain spawn.

  • Cons: Slower colonization, increased risk of contamination.

  • Best For: Experienced growers who can manage contamination risks.

Tips for Maximising Mushroom Yield

  1. Maintain Proper Humidity and Temperature: Mushrooms thrive in high humidity and specific temperature ranges. Use a hygrometer and thermometer to monitor and adjust conditions inside the monotub.

  2. Ensure Adequate Ventilation: Proper airflow prevents the buildup of CO2 and promotes healthy mycelium growth. Ensure to fan 4-6x daily and have the appropriate plugs in.

  3. Practice Sterility: Contamination is the nemesis of mushroom cultivation. Always work in a clean environment, sterilize tools, and wash hands thoroughly before handling your setup.

Troubleshooting Common Issues

  1. Slow Colonization: This could be due to low spawn ratios, inadequate temperatures, or contamination. Check your conditions and adjust accordingly.

  2. Contamination: Mold or bacteria can ruin a monotub. Ensure all materials and tools are sterile and consider using a higher spawn ratio for faster colonization.

  3. Poor Fruiting: If your mushrooms aren’t fruiting well, it might be due to low humidity or poor ventilation. Adjust these factors to improve yields.

FAQs

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1. What is the best grain to use for spawn?

  • Rye is the number one grain for mushrooms as it has a high nutrient content and resistance to contamination. 

2. How often should I mist my monotub?

  • Thoroughly mist your tub 4-6 times daily. Monitor humidity levels and mist when needed to maintain 90-95% humidity.

3. Can I reuse my substrate?

  • Substrates can often be reused, but their nutrient content may be depleted. Supplementing with fresh substrate can help.

By following this guide and experimenting with different ratios, you’ll be well on your way to successful and bountiful mushroom cultivation using the monotub method. Happy growing!​

Where to Find Our Products

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All our products can be found HERE.

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Written by CuriousApeMushrooms ❉

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