Professional Filter Patch Grow Bags

Unicorn mushroom grow bags are durable, autoclavable polypropylene bags designed for sterile mushroom production. Their integrated filter patches allow gas exchange while helping reduce contaminants, making them ideal for grain spawn, all-in-one bags, substrate blocks, and fruiting applications.

Learn About Sizes & Filters →
Made In The USA • Plano, Texas

Choosing the Right Unicorn Bag

Unicorn Bags are professional polypropylene filter patch bags used for grain, substrate, fruiting blocks, and all-in-one style workflows. The biggest differences are bag size, filter rating, filter surface area, and how much gas exchange your process needs. Below you'll find the Unicorn Bags we currently carry along with their typical fill weights and recommended applications.

T Filter · 0.2µm

Best when filtration and protection are the priority. Commonly used for grain spawn and cleaner, slower gas exchange workflows.

A Filter · 0.5µm

A great all-around option with a solid balance of protection and airflow. Commonly used for substrate, blocks, and general mushroom work.

B Filter · 5.0µm

Highest airflow option with less filtration. Often used when extra gas exchange is needed for larger blocks or fruiting applications.

Bag Sizes & Typical Fill Weights

4T Unicorn Bag

4" × 3" × 18" • 0.2µm Filter

Typical Fill Weight: 1–2 lb. Ideal for smaller spawn projects and testing.

10T Unicorn Bag

5" × 4" × 18" • 0.2µm Filter

Typical Fill Weight: 3–4 lb. One of the most popular sizes for grain spawn production.

3T Unicorn Bag

8" × 5" × 19" • 0.2µm Filter

Typical Fill Weight: 5–7 lb. Excellent for larger grain bags and commercial workflows.

14A Unicorn Bag

8" × 5" × 19" • 0.5µm Filter

Typical Fill Weight: 5–7 lb. A versatile all-around bag commonly used for substrate and all-in-one projects.

XLS-A Unicorn Bag

10" × 5" × 24" • 0.5µm Filter

Typical Fill Weight: 10–15 lb. Great for larger substrate blocks and bulk production.

XLS-B Unicorn Bag

10" × 5" × 24" • 5.0µm Filter

Typical Fill Weight: 10–15 lb. Designed for applications requiring increased airflow.

XLS-A Horizon

10" × 5" × 24" • 0.5µm Horizon Filter

Typical Fill Weight: 10–15 lb. Features an oversized Horizon filter patch for enhanced gas exchange.

XLS-B Horizon

10" × 5" × 24" • 5.0µm Horizon Filter

Typical Fill Weight: 10–15 lb. Maximum airflow option with Unicorn's larger Horizon filter design.

Not Sure Which One to Pick?

For grain, start with a T filter. For most substrate or general-purpose work, an A filter is usually the safest all-around choice. If you need more airflow, especially in larger bags, look at the B filter or Horizon filter options.

Smaller micron ratings generally provide more filtration, while larger micron ratings allow more airflow. Filter surface area also matters, which is why Horizon filter bags can move more air even when the micron rating is similar.

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