12qt Shoebox Refill Kit – Clean, Simple, and Ready to Run
2 lb Sterile Grain + 5 lb Substrate — Built for 12qt Shoebox Tubs
What’s Included
- 2 lb Sterile Grain Bag – Choose Corn or Milo (4T Unicorn bag with filter)
- 5 lb Premium Substrate – Hydrated to field capacity
- FREE Self-Healing Injection Port
Why Growers Choose This Kit
- Lab-Sterilized Grain – Sterilized 2.5 hours in SH Scientific autoclaves at 15–17 PSI
- Balanced Ratio – Sized specifically for 12qt shoebox tubs
- Premium Substrate – Clean, consistent hydration and structure
- Streamlined Workflow – Ideal for quick turnaround grows
How It Works
- Inoculate the sterile grain bag.
- Allow full colonization at 70–75°F.
- Mix colonized grain with the included substrate.
- Transfer to your 12qt shoebox tub and allow substrate colonization.
- Introduce fruiting conditions and monitor humidity.
Storage Guidelines
- Store sealed between 45°F and 70°F
- Use as soon as possible for best results
- Do not freeze
Explore Other Grain Options
- Corn Grain Bags – Durable kernels with strong structure.
- Drippy Corn – Nutrient-dense option for advanced growers.
- Millet Grain Bags – High inoculation points for rapid colonization.
Hit the chat button at the lower right for help with orders or product questions.
Legal Disclaimer: For laboratory use only. We assume no responsibility for product misuse. Sales are final and concerns are addressed on a case-by-case basis.
Don't Forget Your
Replacement Monotub Filters
Apply to your fruiting chamber to give your substrate fresh air while maintaining high humidity levels.
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Microppose 1.5" Tub Filters For Mushroom Cultivation
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LARGE Adherable Lid Filters 0.3 micron
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Let customers speak for us
There is nothing simple about this stuff. Its great stuff. Holds moisturizer really well. I just purchased again for my final winter grow. Thanks for the great quality
Packaged really good, did not expect
Good agar! Will order again!
Fast speedy delivery.
As described. Fast and clean.
As described. Fast and clean .
Sterile, nicely packaged, and cool color 😌
the grain: i picked milo took off nicely, 2 cc’s per bag, 5 bags per syringe. Works very nice, bags will be done withing a week. I should break and shake right now but, I think ill wait another week or so. As for the bulk substrate, looks great ive been keeping it in our storage room, its super chilly in there. And, it should work great when the time comes. Personally, ive never had issues with any of the bags ive purchased. I hardly inoc in my SAB anymore, as theres no need I just flame sterilize the needle, and inoculate.
The best , that can be obtained.
They are what they are.
Haha I finally got some before they ran out!
It works 💪
Exactly what i wanted!
Great products!
Absolutely great grains! Everything I have ever purchased from here is amazing and solid 🙌🏽
Everything arrived safely and packaged very thoughtfully. Grain looks great!
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