Chaeto is the nickname for Chaetomorpha algae. It grows only in saltwater and is classified as one of the most used macroalgae to purify water in the reef tank. Chaeto is also called as Green Hair Algae or Spaghetti Algae due to its shape. Once you have a look at them, you will notice that grown-up Chaeto algae look like a ball made up of tangled green spaghetti.
Chaeto works as a natural filter to remove excess nitrates and phosphates from the tank water. It also works to accommodate Copepods and Amphipods. Ensuring the cleanliness of the water, it helps to maintain the water quality in the reef tank.
Though many use Chaeto for the refugium only, you can place them either in the refugium or in the main display tank. They grow very fast in favorable conditions and are hardy in nature. As you can put them anywhere in the system and they multiply pretty fast, you do not need to worry about spending hours taking care of them.