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When preparing the substrate, do it this way: Put the required amount of vermiculite in a bowl (NOT for each jar separately!). Use a spatula or spoon to mix in enough water to saturate the vermiculite to the field capacity, mix well. The field capacity is reached when a small puddle,barely visible, forms at the bottom of the bowl when you tilt it. If it?s bigger than a spoonfull, then reduce it. Then add the appropriate amount of BRF and mix together.(This works best if you use 1/2 cup vermiculite and 1/6 cup BRF per 1/2 pint jar)
The idea is to coat the wet vermiculite particles with the dry powder as you stir the mix with the spatula. This sounds trivial but it makes all the difference.

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