Bristle worms can wreak havoc on a saltwater reef aquarium if their population gets too high. Bristle worms usually reproduce at a fast rate when the aquarium is being overfed and they have a lot of food to eat. If the aquarium is not overfed, they'll die off and eat each other's remains, as the worms are scavengers. If you have a bristle worm problem, there are a number of steps you can take to eradicate them from your tank.
Make a trap for bristle worms out of a small plastic container with a lid. It needs to be big enough to hold the bristle worm, but it shouldn't be too large, as it will need to fit in the tank.
Cut an "x" into the side of the container with a knife. Make the x around the same size as your bristle worm. Push the four triangular-shaped plastic tabs inward.
Add a few small pieces of cooked shrimp to the trap and place it in the tank, allowing it to fill with water. The bristle worm will be able to enter the trap easily but will have a hard time getting out due to the angle of the four plastic tabs on the inside of the container. Bristle worms hide during the day so leave the trap in the aquarium over night and check it in the morning.
Remove the trap from the aquarium and flush the bristle worm down the toilet.
Add a predator to the tank that will kill and eat the bristle worms. Fish that eat predators and are tank-friendly include six line wrasses, disappearing wrasses and dottybacks. These fishes will also be an attractive addition to your reef aquarium, and are gentle enough that they don't eat other fish in the tank.
Add an arrow crab to your tank. Unfortunately, arrow crabs may eat other fish, crabs and shrimp that you are not looking to get rid of. However, if you have a large infestation of bristle worms, an arrow crab is a good predator that can reach into bristle worms' hiding places to find them.
Place a coral shrimp in your aquarium to catch and eat bristle worms. These shrimp are nice to look at and will mate if kept in pairs.