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8-Pack ‘Boomr Bag’ Manure Sterile Bulk Substrate












Media | Horse manure mix |
Moisture content | Hydrated to field capacity |
Carton size | 8 bags (40 lbs) |
Bag weight | 5 lbs each |
A $224 value!
Our best-selling Boomr Bag is a sterile bulk mushroom substrate formulated by mycologists to maximize your mushroom yield. It features a proprietary blend of composted horse manure, coco coir, and several quality substrate supplements (although we keep the exact blend a secret!) Over several years, it has been perfected for dung-loving mushroom species and is widely-trusted by mushroom growers.
Use Boomr Bag in monotubs, filter bags, and outdoor beds. Or, grow mushrooms from the bag or tray in a humidity-controlled grow room or Martha set up.
Spawn to bulk ratio:
We recommended mixing 1 colonized grain spawn bag with 2-3 Boomr Bags. (Higher inoculation rates may improve your success.)
Looking for single bags? Click here.
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- We recommend clean hands, latex or nitrile gloves, and sterile technique when using Boomr Bag to reduce the introduction of contaminants.
- Be sure to mix colonized grain spawn thoroughly into your substrate.
- It is best practice to wait a minimum of 1 week after arrival before using sterile substrates to ensure they were not compromised during transit. Rest assured that your purchase is 100% guaranteed. If your substrate was compromised, we will replace it.
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Boomr Bags should be stored at room temperature out of direct sunlight. No refrigeration is necessary. They can also be stored for several months before use.
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Our Boomr Bags are sterilized in a commercial-grade autoclave. Sterility is verified using biological indicators and temperature sensors.
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North Spore's products shall be used only for lawful purposes. North Spore does not condone Psilocybin (Psilocybe cubensis) or hallucinogenic (magic) mushroom growing in jurisdictions where it is currently illegal.
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Great product the shiping arrived earlier than expected. All in all five star company in my opinion. Ty for the great business

Black gold
Absolutely a awesome substrate, fast colonization a 100% at right moisture content with multiple flushes.

Great product
Will continue to use north spore

Quality product, quality service
I have purchased from Northspore a few times now, and have yet to be disappointed! Good products and they replace any item that’s been damaged in transit. Nowhere else I trust for grains and subs

Boomer Bag Blitz
So I have not added the substrate to my colonized bag yet. Am thinking this weekend. Very excited. I will say that one bag was split open upon arrival, so I contacted NorthSpore and they rapidly replaced the broken one with a new one. The open bag did smell very earthy and looked great so I have high expectations for my B+ strain. Thank you guys!!

8 pack manure substrate
Consistency you can count on.. Always have great results using your substrate and the delivery/processing time was definitely the fastest yet… Love that!! Thank you to everyone at North Spore !! ✌️✌️

The best of the best of the best
Northspore operates on a level well above any competitor. The eight pack of bulk substrate arrived very quickly, and with no hiccups whatsoever. Each pack arrived in perfect condition. Ordering was simple, fast, painless. Shipment is fast and discreet. I can’t recommend this eight pack of bulk manure based substrate any higher. You cannot go wrong with this product or company. They are a notch above all the rest.