Instructions
Pick off the offending hitchhikers. Certain hitchhikers can be picked off the rocks manually. This method isn't the most thorough, because if there is any of the offending matter left in the tank, it can re-grow. Some of the hitchhikers then can be physically picked off are aiptasias, caulerpa taxifolia and rock/hairy crabs.
Trap offending hitchhikers. Once they are trapped in the tank, they safely can be removed. There are many options in the market for commercial traps. Traps work well for bristle worms, mantis shrimp and montipora-eating nudibranchs.
Quarantine the hitchhikers, and then treat with chemicals. There are many chemical treatment options in the market. First, the offending hitchhikers must be picked out or trapped for removal and quarantine. Then, following the directions of your chosen chemicals, the hitchhikers can be eradicated. Chemicals work well for aiptasias/majano anemones, acropora eating flatworms, red bugs, red slime algae and marine itch.
Feed them to other fish. Peppermint shrimp can be used as predators to eat aiptasias/majano anemones. Copperbanded Butterflyfish also can act as predators.
How to Remove a Hitchhiker
Building and maintaining a healthy, beautiful aquarium takes a lot of time, money and patience. The last thing you want is for unwanted and unwelcome creatures to make their home in your aquarium. These creatures, also known as "hitchhikers," can destroy your fish, your tank and even can be harmful to you. While there are some hitchhikers, such as sponges or feather dusters, that add beauty and character to your aquarium; others, such as aiptasias and bristle worms, can be dangerous and should be removed.