To start with, many people are unsure how to pronounce Diatomaceous, so to get things started it is pronounced Die-a-to-may-shus.
They are many grades of Diatomaceous Earth, for filtration media, pests, animals and human internal use known as food grade and or medicinal grade diatomaceous earth.
And its safe to say that only food grade/medicinal grade should be used for human consumption. Not only that but you need to make sure its the fresh water type and not the salt water source as the fresh water source is harder(will discuss why later on). Many of the lower food grade DE will contain high amounts of clay a sediment making the Fossil shell flour brownish is colour, its best to buy the white or off white DE.
As mentioned earlier the harder and sharper the better. As the microscopic DE particles pass through the stomach and intestine they play a two fold stage. 1- they attract and absorb bacteria, fungi, heavy metals and pesticides, which get trapped inside the cylindrical shaped DE and then passed out of the body. 2- the hard and sharp fossil shell cut and dehydrate larger parasites killing them.