Sea Lettuce Macroalgae (Golf Ball Size)

Sea Lettuce Macroalgae (Ulva sp.) is a bright green, leafy marine algae prized for its soft, flowing appearance and fast growth. Its thin, translucent blades resemble terrestrial lettuce leaves, making it an attractive addition to refugiums, sumps, and macroalgae displays.

This versatile macroalgae is highly effective for natural nutrient export. As it grows, Sea Lettuce absorbs dissolved nitrate and phosphate from aquarium water; regularly harvesting excess growth physically removes those nutrients from the system. Its leafy structure also provides shelter and grazing space for beneficial microfauna such as copepods and amphipods.

Aquarium Benefits

• Helps manage nitrate and phosphate through rapid growth and routine harvesting.

• Provides a natural, nutritious supplemental food source for tangs, rabbitfish, angelfish, snails, sea urchins, and other herbivores.

• Creates shelter for pods and other small beneficial organisms.

• Can be grown free-floating, allowed to attach to rock or rubble, or gently tumbled in a properly sized refugium.

• Works especially well in established marine systems with available nutrients and strong refugium lighting.

Care Requirements

• Lighting: Moderate to high; brighter lighting supports dense green coloration and faster growth.

• Water flow: Moderate flow is ideal to keep detritus from collecting in the blades and to bring nutrients to the algae.

• Placement: Best in an open refugium, sump chamber, or planted marine display where it cannot clog pumps or overflow screens.

• Nutrients: Requires available nitrate, phosphate, and trace elements. In ultra-low-nutrient systems, growth may slow, pale, or decline.

• Maintenance: Harvest small portions regularly rather than allowing a dense mass to fill the entire chamber. This maintains steadier growth and more consistent nutrient uptake.

Important Notes

Sea Lettuce is delicate and readily grazed, so it may disappear quickly in a display containing hungry herbivorous fish or invertebrates. Rinse or quarantine new macroalgae before introduction, when possible, since algae can carry hitchhikers, eggs, or nuisance organisms.