Does fine vermiculite hold more water than coarse?
It has been a consent among the users of the PF-Tek, that the fine vermiculite can hold more water than the coarse variety. I wanted to quantify this, and made a test: 120 ml of vermiculite were measured, weighed and then water was added to it until the vermiculite was saturated.(according to the PF-Tek for Simple Minds). The 2 varieties used are the ones in this photo: Test results: Fine variety: 120 ml vermiculite, weighs 14 g, can hold 54 ml water. Coarse variety: 120 ml vermiculite, weighs 14 g, can hold 46 ml water. As you can see, the water holding ability varies considerably between the 2 varieties. If you don’t take this into account when preparing substrate, it will be either too wet or too dry.
