Dubtub TEK: Full Guide

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🌱 Dubtub tek allows beginners to grow mushrooms at home with just two plastic tubs and minimal equipment.
💧 Fruiting chambers like dubtubs maintain 85–95% humidity crucial for healthy mushroom development.
🍄 Psilocybe cubensis and oyster mushrooms thrive in dubtub setups due to their adaptability.
💨 Inadequate fresh air exchange is the leading cause of malformed or stalled mushroom growth.
🧂 CV mix (coco coir + vermiculite) is the most effective and beginner-friendly substrate for dubtub cultivation.

Dubtub TEK (aka “dub tub” or double-tub technique) is a beginner-friendly method to grow mushrooms using two plastic tubs and minimal gear. It’s ideal for someone starting indoors, looking to experiment, or trying container growing in tight spaces. For growers already using Mushroom Grow Bags, dubtub tek offers a smooth next step since colonized bags can be transferred easily into the tub setup. And when you’re ready to expand beyond dubtubs, our Monotubs provide a larger, more controlled fruiting chamber for consistent harvests at scale.

What Is Dubtub Tek?

Dubtub TEK (short for “double tub technique”) uses two identical plastic tubs—one acting as a base and the other inverted as a lid—to create a compact mushroom fruiting chamber. This setup retains high humidity, allows diffuse light, and supports fresh air exchange (FAE) through small holes covered with polyfill or micropore tape. It’s a low-cost, low-tech alternative to monotub tek or more complex fruiting chambers, with enough control to deliver good flushes in containers or grow bags.

The dubtub originated from online mycology forums, where hobbyists sought minimalist alternatives to bulky or expensive grow systems. It combines elements of the “monotub” and the “shotgun fruiting chamber,” offering a compact, low-cost hybrid.

The top tub usually has holes drilled. These holes are covered with polyfill or micropore tape. This helps air move in and out and stops contamination. Light goes through the clear plastic, which acts like day and night cycles. Misting by hand helps control moisture. This makes a small environment that helps many mushrooms grow. You do not need automatic gear or special rooms with controlled temperature.

Whether you're growing gourmet edible mushrooms or legal species of interest in your jurisdiction, dubtub tek offers reproducible results with minimal input.

Why Choose Dubtub Tek to Grow Mushrooms at Home?

Dubtub tek is becoming the go-to method for aspiring indoor mushroom growers, and for good reason. Here are some qualities that set it apart from other more advanced or commercial grow techniques:

✅ Beginner-Friendly

No experience? No problem. Dubtub setups require almost no technical know-how. If you can assemble a set of plastic containers and know how to mist with a spray bottle, you're already halfway to success.

🧰 Uses Common Household Materials

You don’t need expensive lab gear. Most needed supplies—like storage bins, tape, and sprayers—are already found at home or available at local stores for a few dollars.

🧪 Compatible With Grow Kits

You can place pre-colonized mushroom grow kits from places like Zombie Mushrooms right into a dubtub. You need almost no changes. This means you don't have to inoculate or sterilize your own grain spawn. But, you can always move to that later.

⚙️ Customizable

You can easily change your dubtub setup to fit your mushroom species and where you live. Is it too dry? Just mist more. Do you need more fresh air? Drill more holes or fan by hand. It works well in different local environments.

💸 Extremely Cost-Effective

Starting a dubtub setup often costs less than $20. This makes it a low-risk hobby. If you are trying things out or learning, it's good to know failure doesn't cost much. And, success can even save you money by replacing store-bought mushrooms.

📦 Scalable in Small Spaces

Dubtubs stack neatly in closets, cabinets, or under lights. For apartment dwellers, it offers a discreet and space-conscious growing solution.

cross-section of a dubtub setup showing airflow

How Fruiting Chambers Support Mushroom Development

Mushrooms are picky. In the wild, they grow when moisture, temperature, and oxygen are all just right. A fruiting chamber like a dubtub creates these perfect conditions.

Let’s break down the three primary elements it supports:

💧 Humidity

Mushrooms need high humidity all the time to form proper fruit bodies. This helps them avoid drying or cracking. A good dubtub setup keeps the air around 85%–95% humidity. This is like the damp forest floor where many mushrooms grow. Mist the sides of your walls, but not the mushrooms directly. This avoids giving them too much water.

🍃 Fresh Air Exchange (FAE)

Stale air builds up CO₂, which mushrooms exhale as they grow. In a low-FAE environment, you'll notice long, leggy stems or fuzzy mycelium at the base of fruits—a clear sign of suffocation. Dubtubs support manual or passive airflow through drilled holes to ensure your mushrooms "breathe."

🔆 Light

While mushrooms don’t photosynthesize, light helps them orient their growth and signals the start of the fruiting phase. Light should be gentle—like indirect sunlight or a daylight-spectrum LED for 12 hours a day.

🌡️ Temperature

Temperature range depends on the species, but 60°F–75°F is generally optimal for most cubensis and gourmet mushrooms. Storing tubs in a climate-stable room away from heaters or A/C vents is key.

Taken together, these four elements are the foundational science behind how a dubtub functions and thrives.

materials such as transparent storage bins, tape, sprayers, drills

Step-by-Step: How to Set Up a Dubtub Tek Mushroom Chamber

You can assemble a dubtub mushroom fruiting chamber in under an hour. Here's a clear roadmap to follow.

🛠️ Materials You'll Need

2 clear, stackable plastic bins (6-15 quart)
Polyfill or micropore tape (for air hole covers)
Drill or hot nail (to make holes)
Spray bottle filled with distilled water
Sterile substrate (like CV mix)
Colonized grain spawn or grow kit

Optional additions:

Digital hygrometer/thermometer
LED light (5000–6500K)
Tub liner (prevents contamination)

🚧 Instructions

Gather supplies: two clear plastic tubs (6-15 qt), polyfill or micropore tape, spray bottle, colonized spawn or kit, and substrate (CV mix is beginner-friendly).
Drill air holes: make roughly 4–8 quarter-sized holes per tub, cover with polyfill/micropore to allow airflow without contamination.
Fill substrate: mix spawn into substrate, place into bottom tub to ~2–4 in depth. Level gently.
Add lid and begin fruiting conditions: place top tub inverted as lid, maintain 85-95% humidity via misting, indirect light (12-hr cycle), and fresh air exchange (open/vent manually or via holes).
Watch for pins: expect first primordia usually within 7-10 days if conditions are stable.

coco coir and vermiculite substrate for mushrooms

Substrate Options: What Works Best in Dubtubs?

The substrate is your mushroom’s growth medium—think of it as nutrient-rich soil for fungi.

🧪 CV Mix (Coco Coir + Vermiculite)

Dubtub tek and CV mix work very well together. Coco coir has a fiber-rich structure. Vermiculite holds water perfectly. The mix keeps just the right amount of moisture for mushrooms to grow well. Many experienced growers use it for high success rates and consistent results (Rogers, 2019).

💩 Manure-Based Substrates

Composted cow or horse manure is rich in nitrogen, making it ideal for high-yield species like psilocybin varieties. However, it's much smellier, requires pasteurization, and is harder to work with, so not recommended for beginners.

🌾 Straw & Wood Chips

For oyster mushrooms or lion’s mane, these cellulose-rich substrates work great. They must be chopped and pasteurized, but are often cheaper in volume. Straw especially supports aggressive colonizing species.

Want the easy route? Zombie Mushrooms supplies pasteurized, ready-to-go substrate bags tailored to your chosen species.

Picking the Right Containers for Dubtub Tek

Choosing your container wisely improves airflow, light exposure, and stacking convenience.

Guides for Selection:

Material: Use clear plastic for light penetration and visual inspections.
Size: 6 to 15 quarts are ideal for most home growers. Deeper isn't always better—too much depth can slow gas exchange.
Shape: Flat bottoms and straight sides help reduce pooling and create even substrates.

Pro Tip: Sterilize tubs with 70% isopropyl before each grow to prevent contamination.

digital hygrometer inside mushroom growing tub

Maintaining Ideal Fruiting Conditions

Daily care is how you get many mushrooms from colonized tubs. Here are the best ways to do this:

Humidity Control: Mist walls 1-2 times per day; use a hygrometer; aim for 85-95% RH to avoid drying or cracked caps.
Fresh Air Exchange (FAE): Fan or open ventilation holes; avoid stagnant air to reduce mycelium overlay or leggy stems.
Temperature Monitoring: Keep ambient temps between ~60-75°F; avoid sudden drops or heat spikes.
Substrate Depth: Use 2-4 inches of substrate; too shallow dries fast, too deep slows down gas exchange.
Light Exposure: Provide indirect, low intensity light (like daylight LED) for 12 hrs/day; not full sun or overly bright setups.
est between 60°F–75°F.
Avoid placing tubs directly near windows or HVAC systems.

Consistency is king. Try to monitor these parameters morning and evening for best results.

psilocybe cubensis and oyster mushrooms growing

Best Mushrooms to Grow with Dubtub Tek

Not all mushrooms are dubtub-compatible, but here are top-performing species:

🍄 Psilocybe Cubensis

A mycology community favorite due to its forgiving nature and fast growth. Colonizes quickly and responds well to CV mix in dubtubs.

🍽️ Oyster Mushrooms (Pleurotus spp.)

Rapid colonizers. Thrive in various substrates and tolerate wide temperature and humidity ranges.

🦁 Lion’s Mane (Hericium erinaceus)

More delicate, but great results can be achieved with increased airflow and humidity—best for intermediate growers.

Trying different things is good. But always check what your chosen mushroom species needs for its environment first.

Common Dubtub Tek Mistakes to Avoid

Growers often run into similar issues. Knowing these ahead of time boosts your odds:

Over-misting: Drowning substrate invites Trichoderma and anaerobic bacteria.
Ignoring FAE: Causes “fuzzy feet” or stunted primordia.
Shallow Substrate: 2–4 inches is ideal—shallower substrates dry too quickly.

Reddit forums and mycology groups report ~70% success rate on first dubtub attempts when these mistakes are avoided.

comparison between a dubtub and a martha tent setup

Dubtub Tek vs Other Mushroom Fruiting Chambers

Fruiting Chamber	Advantages	Disadvantages
Dubtub	Cheap, beginner-friendly	Requires daily manual input
Monotub	Great for bulk grows	Less flexible, needs more space
Martha Tent	Fully automated setup possible	Expensive and complex
SGFC	Classic starter choice, versatile	Less humidity control

Dubtub is ideal for learners and small-scale growers not ready to automate or scale massively.

Scaling Up: Can Dubtub Tek Be Used for Larger Grows?

Absolutely—within reason.

📈 Strategies to Expand:

Use multiple dubtubs at once in cycles.
Add desk fans for constant FAE on timers.
Include perlite trays or foggers for increased humidity control.

At a certain point—typically beyond four tubs—switching to monotubs or tents may be more efficient. But for learning or micro-scale grows, dubtubs remain the dominant format.

hand wiping contaminated mushroom growing bin

Troubleshooting Dubtub Challenges

Here are fixes to common problems:

Green mold (Trichoderma): Sterilize work surfaces and substrate more thoroughly.
No pinning: Add more FAE or lower temperature slightly.
Stalling colonization: Substrate too dry or contaminated—revisit moisture content and cleanliness.

It's all part of the process—every failure teaches better technique.

FAQ Section

What is Dubtub Tek?
A simple double-tub fruiting chamber using two plastic bins, creating humid and controlled conditions using holes and coverings for air exchange.
Dubtub vs Monotub — which is better?
Dubtub tek is cheaper and simpler, great for beginners or limited space. Monotub offers bigger yields but needs more substrate, more careful moisture & airflow management.
Which mushrooms grow best in dubtubs?
Species like Psilocybe cubensis and oyster mushrooms generally respond well to the dubtub method because of its forgiving environment.
How long until pins appear in a dubtub setup?
Under good conditions (substrate, humidity, airflow), primordia often appear in 7-10 days after setting up the dubtub.
Common mistakes with dubtub tek?
Over-misting, lack of airflow (FAE), substrate too shallow, or using non-sterile tubs/hands can lead to contamination or poor fruiting.

So, Is Dubtub Tek the Best Way to Grow Mushrooms?

For anyone new to growing mushrooms at home, dubtub tek is the best way to start. It combines simplicity, low cost, and good results into one smart design. More advanced methods exist, but none match the dubtub’s low barrier to entry or its ability to change. You might be growing your food, or studying fungi as a hobby, or trying out new species. In any case, using a dubtub makes sense.

At Zombie Mushrooms, we are here to help every step of the way. We have spawn bags, substrates, and full kits. Look through our catalog and start your dubtub project.