Chaetomorpha (refugium algae)

Care at a glance

Chaeto is not an ornamental alga but a workhorse: a tangle of stiff green filaments you let tumble in a refugium or sump. As it grows it takes up nitrate and phosphate, so you literally harvest those nutrients out of the system.

Give it its own light and some flow so the ball turns slowly and gets light all round. Regularly cut away half and discard it; only by harvesting do you actually remove the absorbed nutrients from your aquarium.

Related species

• CaulerpaCaulerpa prolifera
• Halimeda (money plant)Halimeda sp.
• Gracilaria (red macroalgae)Gracilaria sp.
• Sea grapes (ornamental macroalgae)Botryocladia sp.
• Sea lettuce (ulva)Ulva lactuca
• Dragon’s breath algaeHalymenia sp.