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How to Get Rid of Bristle Worms?

Bristle worms are a common presence is a saltwater reef tank. These small worms can be a help or a hindrance, depending on how many you have. One or two are okay but too many can contaminate an aquarium and negatively affect the biological balance. So, how do you get rid of them (if necessary)?

There are a few ways to rid your marine tank of bristle worms. You can make your own worm trap using a plastic bottle. You can also wait until the evening when worms emerge from their hiding places and remove them with a tweezer. As well, you can add predatory fish to the tank to eat the worms.

Now that you know there are 3 easy ways to remove bristle worms from your saltwater aquarium, let’s explore this topic further and in more detail. Together we’ll discover what these creatures exactly and what they look like, where they come from and how they get into a contained aquatic environment, if they’re harmful or helpful to a reef tank setup, and how to kill them.

So, if you’re ready to learn more about bristle worms and how they affect a reef tank set-up, then let’s get started!

What are Bristle Worms?

Bristle worms are tiny caterpillar-like worms that live in the dark crevices of live rock and underneath the sandy substrate in a saltwater tank. The ‘bristle’ in the name is derived from the coarse hairs that covers it. These reef rock ‘pests are unsightly and can wreak havoc on a marine tank if overpopulated.

On the other hand, a few bristle worms can be beneficial in helping to keep a marine tank clean. They’re scavengers that feast upon decaying organic matter as well as debris in a saltwater tank. They’ll also eat algae which, if overgrown, can affect both the aesthetic appearance and ecological balance in the tank.

A large bristle worm.

Where do Bristle Worms Come from?

Bristle worms hide in the tiny holes and crevices in reef rock. They typically go unnoticed and therefore are introduced unknowingly into a marine tank environment. These aquatic creatures are nocturnal and so skilled at hiding that it may take months for an aquarist to detect their presence.

What Causes Bristle Worms Overpopulation?

An unclean aquatic environment is likely the main cause of a bristle worm infestation. Algae overgrowth in the tank can be the culprit. Keeping the aquarium well maintained and free of detritus with regularly cleanings and partial water changes is the best way prevent bristle worm overpopulation.

Another cause of bristle worm overpopulation is overfeeding fish. Too much leftover or rotting food will increase their numbers. The greater the food supply in the tank, the more these creatures will multiply. Making sure to remove any uneaten food from the substrate as soon as possible will help control them.

Are Bristle Worms Harmful in an Aquarium?

Bristle worms can be harmful to both fish and their human keepers alike. Though not aggressive by nature, they can sting tankmates with their bristles if they feel threatened. They can also bite out of fear when handled by humans. It’s best to remove aggressive bristle worms as soon as possible.

Are Bristle Worms Helpful in an Aquarium?

Bristle worms are scavengers that feed off leftover food, decaying organic matter, and detritus in a saltwater aquarium. A few in a tank is okay but too many will increase the bio-load and pollute the aquatic environment with ammonia and other toxins.

Should You Remove Bristle Worms from an Aquarium?

If you have one or two non-aggressive bristle worms, then leave them in the tank to help with waste management. If you have a predatory species that’s attacking its tankmates, remove it immediately. More than two can lead to an infestation so remove the extras from the aquarium as soon as possible.

What Kills Bristle Worms?

Bristle worms are killed by predatory fish in an aquarium. Since they feast on detritus in the tank, they’re self-sufficient feeders and can’t simply be killed by limited their food supply. Apart from carnivorous tankmates, the only way to kill these resilient aquatic creatures is to trap them and remove them.

A flame hawkfish looking at the camera.

How to Get Rid of Bristle Worms in an Aquarium using Predatory Fish?

There are several aquatic creatures you can add to your marine tank to prevent bristle worms from overpopulating. Both saltwater fish and invertebrates will dine on bristle worms in captivity. These include the following:

Predatory or carnivorous marine fish of almost any species will likely feast upon unwanted bristle worms. Be careful when introducing new, potentially aggressive fish to an established reef tank and make sure to research the species in advance to determine if its right for your marine tank set-up.

How to Get Rid of Bristle Worms in an Aquarium using a Plastic Water Bottle?

To rid your saltwater tank of unwanted bristle worms, create a do-it-yourself worm trap. You’ll need a plastic bottle, box cutter, scissors, straws, and some brine shrimp (bait). Begin by cleaning the bottle thoroughly with hot water to prevent contaminating or altering the parameters of the tank water.

Next, cut 3 X’s on one side of the bottle using your box cutter. Then, take your scissors and cut 3 holes on the same side just big enough for the straws to fit through. Repeat this process on the other side – just make sure the holes aren’t directly across from each other but rather slightly offset.

When you’re finished cutting the holes, insert the straws on each side of the bottle. Add some bait to the trap and then place it on the substrate making sure the straws are touching the sand. In the morning, check your trap to see if any bristle worms are inside!

How to Get Rid of Bristle Worms in an Aquarium using Tweezers?

Another way to catch bristle worms is to remove them by hand using a tweezer. In the evening, turn on the moonlight feature in the tank and wait for the worms to emerge from their hiding places. Once you see them, take the tweezers, place your hand in the tank slowly, and carefully remove them one-by-one.

To catch bristle worms easier, be sure to bait them. Place a tiny piece of brine shrimp on a rock or an easily accessible spot in the tank. The worms won’t be able to resist and will eventually come out of hiding. Once they do, you can pick them out one-by-one with the tweezers and then discard them.

a bristle worm crawling on a green leaf.

Final Thoughts

To sum-up, there are a couple of easy ways to rid your saltwater tank of unwanted bristle worms. You can make a DIY worm trap using a plastic bottle and some bait or your can remove each worm by hand using a pair of tweezers. You can also introduce carnivorous fish to the aquarium to eat the worms.

I hope this article has answered your questions regarding bristle worms and how to remove them from an aquarium. Thanks for reading. Good luck with your aquarist hobby!

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