CVG Ratio Calculator

Use this CVG Recipe Calculator to work out the exact quantities of coco coir, vermiculite, gypsum, and water for any batch size. Whether you’re scaling up for bulk substrate production or preparing smaller home grow mixes, this tool lets you calculate by weight, volume, or ingredients on hand using the same 10 : 10 : 1 CVG ratio we use at Spore Supplies. Adjust hydration levels and vermiculite grades to match your materials for consistent, field-capacity-ready results every time.

Based on Spore Supplies CVG ratio coir:verm:gypsum = 10:10:1 (by weight). Default hydration 3.809 L per kg dry (editable).
Includes water. Baseline finishes ~20 kg.
How this calculator works
Dry ratio: coir:verm:gypsum = 10:10:1 (by weight). Hydration defaults to 3.809 L per kg dry. Choose a vermiculite grade to auto-set density; fine-tune in Advanced.
  • By Final Weight: enter the finished CVG batch weight – we back-calculate components.
  • By Ingredients: enter dry amounts you have – we compute the largest compliant batch (no water limiting).
  • By Target Volume: enter desired final volume – we solve using densities + hydration.
Tip: Need tub-based volume? Use the Monotub Calculator, then come back here and run “By Target Volume.”

CVG CALCULATOR FAQ:

What does CVG stand for?

CVG stands for Coco Coir, Vermiculite, and Gypsum. CVG is a standard substrate mix used in mushroom cultivation. The calculator uses Spore Supplies’ 10 : 10 : 1 dry weight ratio as the baseline for consistent results.

How accurate are the volume estimates?

This CVG ratio tool uses density values based on measured averages for common grades of vermiculite and coir. Actual results can vary slightly depending on how tightly materials are packed and the brand or flake size used. Adjusting the “custom density” option can improve precision.

Why do I need to choose a vermiculite grade?

Vermiculite’s density changes with particle size. Finer grades pack more tightly and therefore weigh more per litre. Selecting the correct grade helps the calculator predict more accurate volumes and hydration levels.

What hydration level should I use?

The default hydration of 3.809 L per kg dry mix matches the moisture balance we use at Spore Supplies. You can increase or decrease it if your growing environment or species requires a slightly drier or wetter substrate. To get the best hydration level, we recommend hand-squeezing to test for maximum field capacity.

How can I use this with the Monotub Calculator?

First, use the Monotub Calculator to find your tub’s required CVG volume. Then, return here and enter that value under “By Target Volume” to get exact weights of coir, vermiculite, gypsum, and water for your batch.

Find CVG Ingredients:

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Or, Try Ready-To-Use CVG:

  • a bag of sterile cvg substrate by spore supplies for mushroom cultivation
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Spore Supplies

Sterilised CVG Mushroom Substrate Bag

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