What is the difference between a single-stage vs. two-stage regulator?

A single-stage regulator reduces the cylinder’s gas pressure in one step, whereas a two-stage regulator reduces the pressure in two steps, resulting in a more stable and reliable flow of CO₂. A two-stage regulator also helps to prevent “end-of-tank dumps,” in which a nearly empty CO₂ cylinder may dump out the rest of its gas in one go.

For more information, see our full article on CO₂ systems for high tech planted tanks.