Macro Algae

Choose macroalgae around its purpose and growth habit. A refugium intended for nutrient export needs dependable growth and room for harvest, while a visible marine planted display also benefits from contrasting shapes and colors. Loose Chaetomorpha, branching red algae and calcified forms do not all suit the same placement or care routine.

Match lighting and water movement to the selected algae, and keep fragments clear of pump intakes. Growing macroalgae uses nutrients; it can stall or decline when those nutrients become depleted. Test the aquarium and observe growth before adding supplements, especially in a reef where changes also affect corals and other livestock.

Allow access for thinning, remove deteriorating material promptly, and check whether the chosen variety spreads into neighboring rockwork. Calcified algae also depend on suitable calcium and alkalinity. Herbivorous fish, crabs and urchins may consume ornamental growth, so decide whether the algae belongs in the display or a protected refugium before selecting a clipping.