🍄 Free Mushroom Substrate Calculator
Calculate precise CVG recipes, spawn ratios, monotub volumes & harvest yields — instantly.
🌿 Mushroom Cultivation Dashboard
Calculate precise substrate recipes, spawn ratios, and harvest yields
Field Capacity Test
Squeeze a handful of mixed substrate firmly. Only 2–3 drops should escape. Streams = too wet; zero drops = too dry.
Ideal Depth
Fill your monotub to a depth of 3–4 inches for optimal gas exchange and mycelium penetration during colonization.
Spawn Ratio Tip
Higher grain spawn ratios (1:1) colonize rapidly, outrunning mold. Use 1:2 as a safe, proven starting point.
Biological Efficiency
100% BE means 1 lb of fresh mushrooms from 1 lb of dry substrate. Many oysters exceed this easily in ideal conditions.
Multiple Flushes
Expect ~60–70% of total yield in the 1st flush. Subsequent flushes are smaller but still valuable. Soak blocks between flushes.
Optimize Conditions
Maintain 85–95% humidity, fresh air exchanges, and 65–75°F for most gourmet varieties to hit peak BE percentages.
Why Use a Mushroom Substrate Calculator?
- Growing gourmet mushrooms at home requires shifting away from expensive pre-made blocks to bulk mixing.
- Our free mushroom calculator eliminates the guesswork, helping you prepare perfectly balanced growing mediums that colonize rapidly while minimizing the risk of contamination.
The Ultimate CVG Substrate Calculator Recipe
For the vast majority of indoor growers, the gold standard growing medium is a blend of Coco Coir, Vermiculite, and Gypsum (known as CVG). Using a precise
cvg substrate calculator ratio ensures your mix achieves perfect water retention and structural aeration:
Coco Coir: Provides the carbon-rich organic matrix structure that mushroom mycelium loves to digest.
Vermiculite: A naturally occurring mineral that acts like a sponge, locking in vital moisture so your bulk tub doesn’t dry out during the intense first flush.
Gypsum: Introduces essential calcium and sulfur minerals while stabilizing the overall pH levels of your organic matter.
Achieving Field Capacity
- When using our vermiculite coco coir bulk substrate calculator, remember that hydration is everything. Your final mixed CVG should reach “field capacity.”
- To test this, grab a handful of the mixed substrate and squeeze it firmly. Only a few stray drops of water should escape between your knuckles. If it streams out, it is too wet; if no drops appear, it is too dry.
Mastering the Monotub Substrate Calculator Layout
- A monotub is simply a modified plastic storage tote used to mimic ideal fruiting environments. When using a monotub substrate calculator, the primary objective is ensuring your mixed substrate settles at an optimal depth inside the tub—ideally between 3 to 4 inches.