Boomer Shroomer Dry Bulk Substrate for Mushrooms — CVG Mix (Coco Coir, Vermiculite, Gypsum), 9–10 lb Yield

Boomer Shroomer Dry Bulk Substrate is a ready-to-mix CVG blend (coco coir, vermiculite, gypsum) formulated to produce about 9–10 pounds of pasteurized substrate for monotubs and other bulk fruiting systems.

This dry bulk substrate package contains measured components to simplify spawn-to-bulk transfers and reduce preparation time. The mix pairs the water-holding capacity of coco coir with vermiculite’s aeration and gypsum’s pH buffering to create a balanced substrate that hydrates predictably and supports consistent colonization when pasteurized correctly. It arrives dry and compact, making storage and transport easy until you’re ready to hydrate.

How do I prepare this substrate for a monotub grow?

Preparation is straightforward: hydrate with boiling water, let it sit to reach field capacity, then pasteurize for about 24 hours. Once cooled and drained to the right moisture level, mix with colonized spawn and load into your monotub or other fruiting container.

• Add roughly 16 cups of boiling water to the dry mix in a 5-gallon bucket.
• Stir, cover, and allow the material to absorb heat for 30–60 minutes.
• Pasteurize the hydrated substrate for 24 hours, cool, then mix with spawn and case as needed.

What yield can I expect from this package?

This dry CVG blend hydrates to roughly 9–10 pounds of usable pasteurized substrate — commonly enough for two standard monotub setups or multiple smaller fruiting vessels. Yield depends on how compactly you pack tubs and the spawn ratio you use.

• Dry components: 500g coco coir, 500g vermiculite, 100g gypsum.
• Hydrated output: about 9–10 lbs of substrate when mixed to field capacity.
• Typical use: two full monotubs or several trays/filter bags depending on volume per container.

Why does this CVG blend work well for bulk substrate?

The combination of ingredients balances moisture retention, aeration, and chemical stability—helping mycelium spread evenly without becoming anaerobic. This makes it a reliable choice for both new growers and experienced cultivators adapting spawn-to-bulk (S2B) methods.

• Coco coir: holds water while resisting compaction.
• Vermiculite: creates air pockets to improve gas exchange.
• Gypsum: stabilizes calcium and pH for a consistent substrate environment.

How flexible is this substrate for different growing methods?

The dry CVG blend is versatile: hydrate and pasteurize it for monotubs, spread it in trays for bulk fruiting, or fill filter bags for sealed systems. It’s tolerant of standard spawn ratios and can be mixed with supplements if you prefer enriched formulas.

• Works well in monotubs, trays, and filter bags.
• Compatible with typical S2B spawn ratios and procedures.
• Can be used as-is for a clean, simple bulk substrate or amended by experienced growers.

Who is this for: Growers who want a consistent, pre-measured CVG base without weighing and blending raw ingredients. Ideal for beginners who want a reliable introduction to pasteurized bulk grows and for seasoned cultivators seeking a convenient, space-saving dry mix that hydrates to a predictable volume. For product questions or assistance, contact Ashley at ashley@boomershroomer.com.