Many aquarists don’t know what to do when they see detritus worms in their aquarium. If they even recognize these critters, they’re usually not sure if it’s an emergency or something that can be left alone.
Because of this, a lot of misinformation and conflicting advice is shared. This does nothing but result in frustrated aquarists and potentially unhealthy fish.
This guide will teach you about detritus worms as well as your options for getting rid of them.
What are detritus worms?
Detritus worms are small aquarium pests that are often overlooked. They belong to the annelid phylum of worms, which is the same family as earthworms, leeches, and ragworms.
Like common soil worms, detritus worms are segmented. They are whitish-brown in color and look similar to hair. Slender and squiggly, most detritus worms will continue to grow until they are about an inch long.
Believe it or not, debris worms are pretty common! Many aquarists will come across them at some point.
These pests are notorious hitchhikers and can appear out of nowhere. In good aquarium conditions, the worm population remains low or almost non-existent. Surviving worms generally stay out of sight when the tank is in good shape.
But once conditions get crazy, the population explodes!
Debris worms usually live in the substrate. Thanks to their slender bodies, they can easily move between grains of sand or in small pockets made up of pebbles. When their food source is abundant, the worms often work their way to the top layer of the substrate before finally floating through the water column.
You may start to see them drifting all over the tank or get caught in the filters in severe infestations. However, most fish keepers will only notice them if they are sucked into substrate vacuums or under gravel filters.
Author’s Note: Detritus worms are appropriately named from their diet. These small pests feed on decaying plants and animals. They survive on decomposing leftovers and debris that accumulate throughout the tank.
How do they get into your tank?
Seeing those little worms emerge from the substrate can be alarming. However, you should take it as a sign that the water conditions are not good.
Detritus worms usually enter tanks through relatively innocent means. Like snails and other pests, they are adept hitchhikers that easily spread from one enclosed environment to another.
The most common ways they enter aquariums are through fish, plants, and substrates. If you moved substrate from one infected aquarium to another, you could have unknowingly taken hundreds or thousands of worms with you.
The same goes for plants. The worms like to cling to leaves and roots.
Even fish can wear them on their skin!
So why are they suddenly noticeable? Most likely, deteriorating tank conditions are causing the worms to proliferate at a rapid rate.
As we mentioned earlier, detritus worms feed exclusively on plant and animal debris. When that food source becomes abundant, the worms can quickly grow and reproduce. These worms multiply rapidly!
It doesn’t take long for a population of thousands to appear. With no more room below the surface of the substrate to hide, they rear their hideous heads and invade the open sea.
Author’s Note: Even if your aquarium appears clean, that may not be the case. Beyond visible debris, improper water parameters can cause debris worm populations to increase. The two most important factors here are oxygen levels and pH balance.
When the tank gets dirty, ammonia and nitrate levels increase, the water becomes slightly acidic, and oxygen levels decrease. All of these events create a prime environment for detritus worms to flourish.
Are they harmful?
The good news here is that detritus worms are not particularly dangerous.
Author’s Note: It is important to remember that these pests only eat plant and animal waste. While they can be hooked onto your fish and turned upside down for a ride, they do not affect their health in any way.
In fact, having a small and manageable population could benefit your aquarium! Like algae eaters, shrimp, and snails, these guys are part of your tank’s essential cleaning crew. They eat any leftover fish food and help take care of the decomposition process when plants begin to die.
Worms can do a lot to keep the closed environment clean.
With that said, you still want to avoid larger infestations. An overabundance of debris worms is an indicator that something is seriously wrong in the underwater habitat.
The worms themselves will not pose a health risk to your fish. However, the poor water conditions that brought them into the light will! In other words, you should use these worms as an indicator that something needs to change.
How to get rid of detritus worms
Fortunately, getting rid of detritus worms is not as difficult as you might think. The formula is to address the root cause of the problem and then physically remove the worms.
Before we get into some techniques on how to do this, it ‘s important to avoid the urge to use medication. Many hobbyists instinctively take over-the-counter dewormers or worm medications to resolve the problem. While that may sound like a good idea, it can lead to even worse problems down the road.
Dewormers do not work on detritus worms. They are surprisingly resistant to the chemicals in those products.
But what’s worse, the drugs could kill the fish! Fish do not adapt well to aggressive deworming products. They often cause a full body shutdown and slow death. The last thing you want to do is wipe out your fish community with an outbreak of worms!
Instead of deworming products, opt for a more natural alternative.
Tackling debris worm outbreaks takes a lot of time and effort, but the steps you take can go a long way in helping your fish move forward.
The first thing you should do is clean the tank. These worms thrive when conditions are not great. So the natural solution is to improve the underwater environment and make it a healthier place for your fish to live.
Start by removing algae buildup along the sides of the aquarium (algae eaters can also help with this). Use a scraper or brush to gently dislodge algae blooms. Don’t use scouring pads or anything that might have a touch of soap.
You can then use a siphon system to suck up some of the loose algae. Then vacuum the substrate well. This is where you’re going to get a good chunk of the worms out of the way.
Author’s Note: As you vacuum, you should suck up tons of worms that you can then get rid of. Don’t be afraid to really get in there and treat as much of the substrate as possible without damaging the plants.
If you have artificial decorative items, take them out for disinfection. You can use an all-natural disinfectant to kill harmful bacteria and pathogens that live on your surface. Alternatively, you can let it soak in a bleach solution for about 15 minutes. Just be sure to rinse it well before adding it back to the environment.
However, we recommend keeping artificial decorations out of the tank while you continue to clean.
Getting rid of detritus worms by purging the tank should be a multi-day process. On the first day, you can take care of all the visible dirt. This includes removing algae from the glass, cleaning and examining the filter, and sanitizing the lid.
In the next few days, you should also do several water changes.
Performing a slow and constant water change is essential. You can’t replace all the water at once and expect your fish to adapt just fine. Even if you put them in pristine water, your fish will experience tons of stress and shock from the sudden environmental change.
It is best to do partial water changes over the course of four days or so. Do about 25 percent each day until you stabilize oxygen levels and remove the most ammonia and nitrates.
If you want to be even more careful, you can limit water changes to once a week. With this technique, you are preserving all the beneficial bacteria that your fish need to thrive. You can always restore the cycling environment over time, but some aquarists like to take it slow to ensure that the maturity of the tank is not lost.
The course of action that is right for you will depend entirely on the severity of the outbreak.
Either way, your tank water conditions should stabilize as you remove excess waste. Continue to vacuum the substrate every day you do a water change. It will take time to remove all the worms, so be patient and watchful.
fish that eat them
Your fish can also do a lot to keep debris worm populations in check! We don’t recommend using your fish to tackle large-scale outbreaks, but adding a few fish that like to eat these pests to your aquarium is a great way to keep them under control.
The truth is that almost all fish will eat the detritus worm. Any species that does not have a sucker mouth will eat them if it comes across the worms floating in the water column.
However, since most worms stick to the substrate, you may do better with a bottom feeder.
Loaches are known to be one of the most prolific detrital worm eaters. They have a healthy appetite for these worms and continually search the bottom of the tank for them.
Prevent these worms from coming back
Once you deal with an outbreak, you need to take steps to prevent future problems. The best way to prevent debris worms from coming back is to reduce the amount of debris that accumulates in the aquarium. Usually that means changing your eating and cleaning patterns.
Follow a routine of substrate vacuuming and water changes. More frequent vacuum sessions will eradicate the worms as they multiply.
It is also important to reduce feeding. The biggest culprit for most hobbyists is overfeeding. When you let scraps fall to the substrate, the detritus worms have direct access to a great food source.
Author’s Note: Feed your fish small meals. In general, it is better to feed several small meals than one large meal.
Then limit the amount of food you give them to what they can eat in two to three minutes (this will change a bit depending on the species). Figuring this out will take some experimentation, but the knowledge is worth it. Limiting the feeding window to just a few minutes will drastically restrict scraps from falling to the bottom.
Finally, try to reduce the biological load of the tank. A large group of community fish may look pretty, but can quickly ruin water conditions. More waste-producing inhabitants only speed up the rate at which the water cracks.
Not only that, but more fish will lower oxygen levels.
By limiting the bioload, changing your feeding habits, and sticking to a cleaning schedule, you can ensure that aquarium conditions remain good. As a result, detritus worms cannot run rampant and reproduce to cause severe outbreaks.
Getting rid of detritus worms in your aquarium isn’t always necessary, but it’s usually a sign that something else needs a look. Do a good honest assessment of the condition of your tank before choosing the best course of action.
If there is any additional information about these worms that you would like help with, you can always ask us. We love having the opportunity to help our readers!