algae eating fish


New member
I have a 46 bowfront that is being taken over by Caulerpa racemosa and Caulerpa cupressoides. I have a Midas blenny, pygmy angel, blackcapped basslet, neon goby, antenna goby, and percula clown. I would like one more small fish that would munch on the caulerpa so that I would not have to prune it so much. Its way out of control and grows back as soon as I weed it. If anyone has any other suggestions I would welcome them. Thanks
You are not likely to find a fish that will graze consistently on species of caulerpa. It is a fairly tough algae with very good chemical defenses. I haven't personally kept a grazer that would feed on caulerpa. Long spined urchins are supposed to mow through just about everything. Sea slugs sold seasonally as "Lettuce Nudibranches" are also supposed to eat it, but they have a fairly short lifespan.

I'd recommend that during your next water exchange you manually harvest as much of the caulerpa as you can. Remove the rock from the tank, pull off the algae, scrub off the holdfasts with a stiff (wire) brush, rinse the rock in the old water (water you intend to throw away), and return the rock to the tank. That should slow it down for a while.

If it were me, for a small tank, I'd just manually remove it. There is a lot of nutrients tied up in the Caulerpa, and if it's grazed, most of those locked nutrients gets returned to the tank water to feed some other plant growth. In time you might want to displace the plant growth to a separate tank like a refugia, where the plants will be more conveniant to harvest.