How to Build a Still-Air-Box (SAB)

How to Build a Still-Air-Box (SAB)

A Still-Air-Box or SAB is a clear container that restricts airflow and reduces airborne contaminants such as bacteria and spores. It's a crucial tool for mycology enthusiasts, particularly when working with agar cultures, grain spawn, and other sensitive projects. While it's not a foolproof solution, a well-sterilized Still-Air-Box can significantly enhance the success rate of your mycology endeavors.

Understanding the Importance of a Still-Air-Box

The SAB acts as a protective bubble against airborne contaminants. We are surrounded by air filled with bacteria, spores, and other potential threats that can outcompete young mycelium. They move with the air currents and gradually descend to the ground. By creating a still-air environment and sterilizing surfaces, we can establish a safer working space for our mycology projects.

The armholes can be seen as the Achilles heel of the SAB. Micro air currents from entering and exiting the SAB may introduce contamination. To mitigate this risk, minimize the frequency of entering and exiting the SAB and sterilize regularly.

When Do You Need a Still-Air-Box?

The early stages of mycelium and spore development are highly susceptible to contamination. Therefore, using a Still-Air-Box or flow hood is essential when working with agar, liquid cultures, spore syringes, grain spawn, and other projects involving young, uncolonized mycelium. Generally, once your grain spawn is fully colonized and ready to introduce to a bulk substrate, the mycelium is robust enough to fend off infections. As a personal rule, if a project fits inside the SAB, then work there.

Building Your Still-Air-Box: A Step-by-Step Guide

Creating a Still-Air-Box is a relatively straightforward and budget-friendly DIY project. With the right tools, you can have a fully functional SAB in about 10 minutes. In this walk-through, we're focusing on converting a clear plastic tote into a SAB using a hole saw kit, a tool that is also helpful for other mycology projects like modified mono-tubs.

Tools & Supplies

  1. Drill
  2. Sharp Knife/Razor Blade
  3. Hole Saw Kit (This is what I use)
  4. Large Clear Tote (70+ quarts recommended)

Safety Tips

Always prioritize safety when working with tools. Wear eye protection, be aware of your hand positions, and avoid inhaling any toxic fumes from melting plastic.


  1. Still-Air-Box Determine Armholes
    Mark Armholes Position

    Start by identifying the desired center point for each armhole. For the most comfortable use, place the armholes at approximately shoulder width apart. After marking the center points, ensure both armholes are symmetrically aligned to guarantee a balanced design.

  2. Attach Hole Saw Bit to Drill
    Prepare the 4-Inch Hole Saw
    1. Fix the metal plate ensuring the prongs face outward.
    2. Slide the drill bit through this metal plate.
    3. Secure the hole saw by fastening the bolt onto the drill bit.
    4. Mount the entire hole saw bit assembly to your drill.
    5. Ensure all components are firmly attached.
  3. Drilling the Armhole
    Initiate the Drilling Process

    Position the drill bit over the marked center from Step 1.

    As you stabilize the tote with one hand, be cautious to keep it away from the drill's trajectory. The pliability of the plastic makes it susceptible to unexpected movements during drilling.

    Begin drilling slowly until the drill bit punches through the center mark and the teeth of the saw touch the plastic.

  4. Using the Hole Saw to Cut Through
    Complete the Hole

    With the hole saw making contact with the tote, initiate slow drilling. It's vital to maintain a gentle pace to prevent the plastic from cracking which could ruin the project.

    Continue the process, applying a steady pressure, until you've cleanly cut through the tote.

  5. Removing the Plastic Debris
    Safeguarding Against Hazards

    To prevent any injury, refrain from extracting the plastic circle from the hole saw manually while it remains on the drill. Opt for either detaching the entire hole saw bit or using needlenose pliers while running the drill in reverse to safely remove the debris.

  6. Drilling the Second Armhole
    Creating the Second Armhole

    Follow the same procedure for the second hole. However, be aware that the tote might now exhibit increased flexibility due to the first hole.

  7. Smoothening the Edges
    Smoothening the Edges

    For optimal safety and aesthetics, utilize a deburring tool or sandpaper to smooth out any sharp or uneven edges around the holes. Ensure that there are no fragments or particles left inside the tote.

  8. Finalized Still Air Box
    Completion & Sterilization

    Your Still Air Box is now ready. To ensure it's devoid of contaminants, consider wiping it down with a 10% bleach solution or isopropyl alcohol. Store it in a clean, dry place to ensure its longevity and efficiency in mushroom cultivation.

How to Use a Still Air Box (SAB)

  1. Preparation: Begin by cleaning the surface where you'll be placing the SAB. This reduces the risk of contaminants in the surrounding environment.
  2. Disinfect the SAB: Before each use, thoroughly clean and disinfect the inside of the SAB. You can use a 10% bleach solution or 70% isopropyl alcohol. Ensure the SAB is dry before placing any materials inside.
  3. Gather Your Materials: Assemble all the items you'll need for your work, such as petri dishes, spore syringes, or grain jars. Having everything ready ensures you won't need to leave the SAB during the process, reducing exposure to contaminants.
  4. Glove Up: Wear gloves, and make sure to disinfect them with isopropyl alcohol. This ensures that any contaminants from your hands don't transfer to the materials inside the SAB.
  5. Work Slowly: Place your arms through the armholes and begin your work. Move deliberately and slowly to minimize air movement, which can stir up potential contaminants.
  6. Limit Time Inside the SAB: Try to complete your tasks efficiently. The longer the SAB is open or in use, the higher the risk of contamination.
  7. Finalize and Seal: Once you're done, seal any containers, petri dishes, or jars you've worked with immediately. This prevents contaminants from settling on them once they're outside the SAB.
  8. Clean Up: After every session, remove all tools and waste. Wipe down the inside of the SAB with a disinfectant to prepare it for the next use.
  9. Store Properly: When not in use, keep the SAB in a clean and dry location. This ensures its longevity and maintains its cleanliness for future uses.

Remember, the goal of the SAB is to create a contaminant-free environment. Regular cleaning, careful handling, and efficient working are key to successful mushroom cultivation when using a Still Air Box.

Recommended Accessories

Desk Lamp

Ensure clear visibility while working inside your still-air-box with this adjustable desk lamp. Its focused light makes intricate tasks in mycology a breeze.

Browse Desk Lamps

Dissection Kit

A comprehensive 37-piece Dissection Kit that's a must-have for any mycologist. Its stainless steel instruments serve multiple uses, from specimen preparation to intricate studies.

Stainless Steel Wire Racks

Working in a sterile environment? The Stainless Steel Wire Rack ensures your project remains elevated in a still air box or flowhood, minimizing exposure to falling airborne debris.

Stainless Steel Surgical Tray - 3 Pack

I regularly use and recommend these Stainless Steel Surgical Trays for my mycology work. Their versatility provides a clean and organized surface for an array of tasks.

Portable UV Sanitizer Lamp

UVC light can assist in disinfecting your projects, enhancing the likelihood of successful outcomes. UVC light in the 200-280NM wavelength is effective in eliminating bacteria and viruses.

Exercise extreme caution when utilizing UVC light. Ensure that you never expose your eyes or skin to the light; UVC light is recognized as a carcinogen. My preferred device has a timer feature, allowing me to vacate the room before it begins its operation.

To be perfectly honest, I'm uncertain about the efficacy of the portable UVC lamp I acquired. However, I lean towards erring on the side of caution when engaging in mycology, so anything can help. Here's a comprehensive video titled "How to know if a UVC device will be safe and effective."

How to know if a UVC device will be safe and effective

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