Diatomaceous Earth (D.E.)

[Eden]

I gather you need to be sure to get food grade because of two reasons - one food grade comes from fresh water sources, no one explains why salt water sources are bad, but I would guess it has some sort of undesirable contaminants, and because non-food grade often has toxic substances added - so you wouldn't want to ingest the stuff that is sold for filtering pools.

Silica itself isn't toxic, thought it is drying and you can kill buggies that are sensitive to dehydration with DA and it does carry a warning about breathing it in - it is fine enough to cause silicosis (black lung disease).

I figure I probably eat enough dirt riding around here in the winter... I don't think I need to add any to my diet intentionally...