Perlite Toxicity Myth: Fluoride Concerns and Source Verification

A grower asks if perlite (besides Miracle-Gro) can be toxic due to fluoride. Expert: has heard this but never seen evidence. Their NW perlite (Supreme Perlite) is 100% silica. Vermiculite may have more impurities but is only recommended for Mexican Pinguicula (tolerate higher minerals). Cites article on fluoride in perlite – risk minimal due to constant wetness; rinsing solves it. Fluorine gas release claims are "nutty" – fluorine instantly recombines.