Coco Coir Block (600–650 g) | Mushroom Substrate

Meet our favorite coco coir – the perfect foundation for a powerful, healthy bulk grow. This compact block is made from 100% natural, organic coconut fibers with zero additives. It provides the ideal base for a light, nutritious, and highly absorbent substrate for your mushroom cultivation.

One block expands to around 8–9 liters of substrate once hydrated – perfect for several small tubs or one larger grow. With an optimal pH balance and low EC value, it offers the ideal conditions for vigorous, healthy mycelium growth.

🔥 Easy to prepare with the Bucket Tek method

Preparing coco coir couldn’t be easier. Using the well-known Bucket Tek method, you can create a clean, fluffy substrate in just a few simple steps:

1. Place the block in a cooler or well-insulated bucket or container.
2. Add 3 liters of boiling water.
3. Let it sit for about an hour, then mix thoroughly with a large spoon or spatula to break up clumps and distribute moisture evenly.
4. (Optional) Add a bit of gypsum to buffer the pH and increase aeration.
5. Seal the container and let it rest for 12–18 hours until it cools to room temperature.
6. Test the field capacity: grab a handful of substrate and squeeze firmly.

• • • A small stream of water means it’s perfect.
    • Too much water? Add a bit of vermiculite.
    • Too dry? Add a little more water.
    • Repeat until you hit the right balance.

Your coco coir is now ready to use as a bulk substrate. Mix it with your fully colonized spawn in a monotub or shoebox. Seal the grow tub and allow the mycelium to colonize the substrate at around 21–27 °C — the perfect start to a strong, healthy harvest.

The perfect base for every successful grow

With this premium organic coco coir, you’ll create the perfect environment for healthy, vigorous mushroom growth. Whether you’re a first-time cultivator or a seasoned grower, this substrate provides the reliable foundation every successful bulk grow starts with.

* Heat treatment using the Bucket Tek method is not full pasteurization, but, under the right conditions, often delivers excellent results. Adding the proper amount of healthy, fully colonized mushroom spawn helps prevent unwanted molds and microorganisms from developing.

** For best results, we always recommend proper pasteurization. This ensures no harmful microorganisms remain in the substrate. We cannot be held responsible for poor results caused by the incorrect use of coco coir.