Chaetomorpha

A popular choice for refugium macroalgae among advanced aquarists in the United States is Chaetomorpha. Unlike Caulerpa, Chaetomorpha is multicellular and, as such, is inherently more stable. It can be cut and pruned aggressively with little or no fear of toxins being released or having vegetative crashes. And, like its namesake, it can also simply be thinned gently with ease like strands of spaghetti noodles. It is fast growing and makes an excellent vehicle for nutrient export! It is also highly adaptable to a very wide range of lighting [Tip: illuminate most macroalgae in refugia with at least 1 watt of light per liter of water at depths less than 30 cm]. Like most “vegetable-filter” algae species, moderate to strong water flow is necessary; keep a total water flow of at least 20X turnover of the volume of the culturing vessel. There are many other benefits to spaghetti algae, not the least of which is that it is a superb matrix for the cultivation of microcrustaceans. Aquarists with thick masses of Chaetomorpha in their refugiums get a bounty of zooplankton to feed their corals in their display, assuming the refugiums is kept without predators like fishes on the plankton. This genus is also a rather hardy shipper; trading among aquarists is strongly encouraged to distribute this useful organism in the hobby.

aquariablog’s take: The only macro I cultivate for nutrient export due to it’s relative ease of care and the fact that it won’t go sexual.