Sea lettuce (ulva)

Care at a glance

Sea lettuce consists of thin, bright green sheets no more than two cell layers thick, which makes them translucent like tissue paper. It grows extremely fast and is therefore an excellent absorber of nitrate and phosphate.

At the same time it is one of the best plant foods: tangs, angelfish and urchins eat it eagerly. Grow it in a refugium with light and flow and harvest regularly; whatever you take out removes the absorbed nutrients from the system for good.

Related species

• Dragon’s breath algaeHalymenia sp.
• Sea grapes (ornamental macroalgae)Botryocladia sp.
• Gracilaria (red macroalgae)Gracilaria sp.
• Shaving brush plantPenicillus capitatus
• Halimeda (money plant)Halimeda sp.
• Mermaid’s fanUdotea sp.