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, there’s a lot of misinformation and conflicting advice being 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.
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What Are Detritus Worms?
Detritus worms are small aquarium pests that often go overlooked. They belong to the annelid phylum of worms, which is the same family as earthworms, leeches, and ragworms.
Like those common soil-based worms, detritus worms are segmented. They are whitish-brown in color and have a hair-like look. Thin and wriggly, most detritus worms will continue to grow until they reach about an inch in length.
Believe it or not, detritus worms are actually quite common! Many aquarists will encounter them at some point.
These pests are notorious hitchhikers and can appear out of nowhere. In good aquarium conditions, the worm population stays low or nearly non-existent. Worms that do survive usually remain out of sight when the tank is in good shape.
But once conditions go haywire, the population explodes!
Detritus worms typically live in the substrate. Thanks to their thin bodies, they can easily wriggle between grains of sand or in small pockets formed by pebbles. When their food source is abundant, the worms will often make their way to the substrate’s top layer before eventually floating through the water column.
You can start to see them drifting throughout the tank or getting caught in filters in severe infestations. However, most fish-keepers will only notice them if they get sucked up in substrate vacuums or under-gravel filters.
Author Note: Detritus worms are appropriately named after their diet. These tiny pests feed on decomposing plants and animals. They survive on decaying leftovers and waste that accumulates throughout the tank.
How They Get Into Your Tank
Seeing those tiny worms emerge from the substrate can be alarming. However, you should take it as a sign that water conditions are not in good shape.
Detritus worms usually enter tanks by relatively innocent means. Like snails and other pests, they are skilled hitchhikers that easily spread from one closed environment to the next.
The most common ways they enter aquariums are through fish, plants, and substrate. 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 latch onto leaves and roots.
Even fish can carry them on their skin!
So, why are they suddenly noticeable? Chances are, declining tank conditions are causing the worms to proliferate at a rapid pace.
As we mentioned earlier, detritus worms exclusively feed on plant and animal waste. When that food source becomes abundant, the worms can grow and reproduce rapidly. These worms multiply fast!
It doesn’t take long for a population well into the thousands to appear. With no more room beneath the surface of the substrate to hide, they rear their ugly heads and invade the open water.
Author Note: Even if your aquarium appears clean, that might not be the case. Beyond visible waste, improper water parameters can cause detritus worm populations to boom. The two biggest factors here are oxygen levels and pH balance.
When the tank becomes filthy, ammonia and nitrate levels spike, the water becomes slightly acidic, and oxygen levels fall. All of these events create a prime environment for detritus worms to flourish.
Are They Harmful?
The good news here is that detritus worms aren’t particularly dangerous.
Author Note: It’s important to remember that these pests only eat plant and animal waste. While they may latch onto your fish and inverts to hitch a ride, they don’t affect their health in any way.
In fact, having a small and manageable population might actually benefit your aquarium! Like algae eaters, shrimp, and snails, these guys are part of your tank’s essential cleaning crew. They’ll eat up any leftover fish food and help take care of the decomposition process when plants start to die off.
The worms can do a lot to keep the closed environment clean.
With that being said, you still want to avoid larger infestations. An overabundance of detritus worms is an indicator that there’s something seriously wrong with the underwater habitat.
The worms themselves aren’t going to pose a health risk for your fish. However, the failing water conditions that brought them to the light will! In other words, you should use these worms as an indicator that something needs to be changed.
How To Get Rid Of Detritus Worms
Fortunately, getting rid of detritus worms isn’t as difficult as you might think. The formula is to address the root cause of the problem then physically remove the worms.
Before we get into some techniques on how to do that, it’s important to avoid the urge to use medications. Many hobbyists instinctively grab dewormers or over-the-counter worm medications to solve the problem. While that might seem like a good idea, it can lead to even worse problems moving forward.
Dewormers don’t work on detritus worms. They’re surprisingly resilient against the chemicals in those products.
But even worse, the medications could kill your fish! Fish don’t take well to harsh dewormer products. They often cause full-body shutdown and slow death. The last thing you want to do is eradicate your fish community over a worm outbreak!
Instead of deworming products, go for a more natural alternative.
Addressing detritus worm outbreaks takes a lot of time and effort, but the steps you take can do a lot to help your fish going forward.
The first thing you should do is clean the tank. These worms flourish when conditions are not excellent. 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 help with this as well). Use a scraper or a brush to dislodge algae blooms gently. Do not use scouring pads or anything that could have a hint of soap in them.
Next, you can use a siphon system to suck up some of the loose algae. Then, vacuum the substrate thoroughly. This is where you’re going to get a good portion of the worms out of the way.
Author Note: As you vacuum, you should suck up tons of worms that you can dispose of later. Don’t be afraid to really get in there and treat as much of the substrate as possible without harming plants.
If you have any artificial decorative items, take them out for sanitization. You can use an all-natural sanitizer to eliminate harmful bacteria and pathogens living on its surface. Alternatively, you can let it soak in a bleach solution for about 15 minutes. Just make sure to rinse it off thoroughly before you add it back into the environment.
However, we recommend keeping the artificial decorations out of the tank as you continue cleaning.
Getting rid of detritus worms by bleaning the aquarium should be a multi-day process. On the first day, you can take care of all the visible gunk. This includes removing the algae off the glass, cleaning and examining the filter, and disinfecting the lid.
In the next several days, you should also perform several water changes.
Performing a slow and steady water change is paramount. You can’t replace all of the water at one time and expect your fish to adjust without any issues. Even if you put them in pristine water, your fish will experience tons of stress and shock from the sudden environmental change.
It’s best to perform partial water changes over the course of four days or so. Do about 25 percent each day until you stabilize the oxygen levels and get rid of as much ammonia and nitrates.
If you want to exercise even more caution, you can limit water changes to once every week. With this technique, you’re preserving all the beneficial bacteria that your fish need to thrive. You can always restore the cycled environment over time, but some aquarists like to take things slow to ensure that the tank’s maturity isn’t lost.
The proper course of action for you will depend entirely on the severity of the outbreak.
Either way, your tank’s water conditions should stabilize as you remove excess waste. Continue to vacuum the substrate every day that you perform a water change. It will take time to remove all of the worms, so be patient and vigilant.
Fish That Eat Them
Your fish can do a lot to keep detritus worm populations under control as well! We don’t recommend using your fish to address large-scale outbreaks, but adding some fish that like to make a meal of these pests into your aquarium is a great way to keep them under control.
The truth is that pretty much all fish will snack on the detritus worm. Any species without a sucker-style mouth will eat them if they run into the worms floating in the water column.
However, because most worms stick to the substrate, you may fare better with a bottom-feeder.
Loaches are known for being one of the most prolific detritus worm eaters. They have a healthy appetite for these worms and continually search for them among the tank’s bottom.
Preventing These Worms From Coming Back
Once you take care of an outbreak, you need to take steps to avoid future problems. The best way to prevent detritus worms from coming back is to reduce the grime that accumulates in the aquarium. That typically means changing your feeding and cleaning patterns.
Stick to a routine of substrate vacuuming and water changes. More frequent vacuum sessions will eradicate worms as they multiply.
It’s also important to scale back on feeding. The biggest culprit for most hobbyists is overfeeding. When you let leftovers fall to the substrate, the detritus worms have direct access to a great source of food.
Author Note: Feed your fish small meals. It’s generally better to feed multiple small meals than one big one.
Then, limit the amount of food you provide to what they can eat in two or three minutes (this will change a bit depending on the species). Figuring this out will take some experimentation, but the knowledge is well worth it. Limiting the feeding window to only a few minutes will dramatically restrict the leftovers that fall to the bottom.
Finally, try to reduce the bioload of the tank. A large group of community fish might look pretty, but it can quickly ruin the water conditions. More waste-producing inhabitants only speed up the rate at which the water sours.
Not only that, but more fish will make the oxygen levels deplete.
By limiting the bioload, changing your feeding habits, and sticking to a cleaning schedule, you can ensure that the aquarium conditions stay in good shape. As a result, detritus worms can’t 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. Take a good honest assessment of the state of your tank before choosing the best course of action.
If there’s some additional information about these worms that you’d like help with, you can always ask us. We love getting a chance to help out our readers!