Charcoal creates an airy soil, aerating both the soil and water. Charcoal helps prevent a musty odor in terrariums and helps prevent fungas and bacteria. Charcoal will help lesson mineral buildup should you accidently use mildly contaminated water. We sell it in 1/4" - 3/8" pieces.
We recommend adding it to Nepenthes and Cephalotus soil, along with all terrariums. Terrariums should have a Charcoal/Perlite mix as a base layer. A 1/6 Charcoal/Perlite mix or so generally does fine.
Generally lasts forever.
Hard to find in most locations. Fine horticultural charcoal is generally available. This larger size works better though.
We offer all of the listed carnivorous plant soil parts, and various mixes thereof, by the quart and gallon. Click the "CP Soil" link above to go to the store. You can learn about other carnivorous plant soils by clicking on their names above. Which is highly recommended.