Detritus Worms in Aquariums – Everything You Should Know

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Detritus worms are tiny, adaptable, can appear out of nowhere, thrive in murky water and unclean tanks, and are scary. Most people will only notice them when the infestation is well underway. You can see them floating in your tank or lurk around the substrate, making for quite a scary and alarming sight.

But should you panic? What exactly are Detritus worms, and are they harmful to the environment, tank inhabitants, or humans? Today’s article will discuss Detritus worms, how to prevent them, manage their presence, and, more importantly, how to minimize or eliminate the infestation.

What are Detritus Worms?

Detritus worms rank as aquarium pests, typically appearing in unclean tanks with dirty water and unstable environments. They are gross and repulsive, but that’s about it. Detritus worms aren’t necessarily harmful to the environment; on the contrary, they can be quite beneficial.

That’s because, like most worms, Detritus are scavengers, feeding off of dead matter, plant and animal-sourced alike. Detritus worms thrive in dirty habitats filled with dead plants, rotten algae, and dead fish. They can appear in your tank if you don’t perform regular maintenance, remove dead matter, and consider weekly water changes.

They are typically no reason for concern so long as you contain the infestation. They will become a problem in larger numbers, but that already suggests abhorrent tank conditions why are unfit for any aquarium lifeform. Without some notable exceptions, Detritus worms included.

How do Detritus Worms Get Into Fish Tanks?

There are 3 primary ways that the Detritus worms can reach your tank:

  1. Via your fish – The Detritus worm won’t infect the fish since it’s not a parasite but an environmental pest. It can, however, use fish as transportation to travel between different environments. You may not even see them on the fish since they can be quite small, especially in their larvae phases. This can lead you to introduce the worm to your tank without even realizing it. To prevent this, quarantine the newly-bought fish at least 24 hours before adding them to the main tank. This will give you plenty of opportunity to check the fish for disease, parasitic infections, or any other problems that may prove detrimental to the environment or other tank inhabitants.
  2. Via plants – It’s common for the Detritus worm to arrive in a new tank via unclean plants. The worm will find shelter on the plant’s leaves or roots and escape into the substrate once you’ve settled the plant in your tank.
  3. Via the substrate – Unclean, dirty substrates can also carry various lifeforms, including Detritus. This happens when dirty substrates are moved from one tank to another without cleaning them properly before use.

As a side note, you might not notice Detritus worms in the initial several weeks of infestation. These worms take shelter inside the substrate since that’s where all the dead matter and food residues end up eventually. They will only show themselves occasionally to pick up food leftovers and then get back in.

If you spot them swimming freely in the water, know that the infestation is already severe. At this point, you must consider finding a solution to the problem.

How to Get Rid of Detritus Worms?

If you’re not a fan of Detritus worms (and no one is), it is imperative to get rid of them fast. In this sense, you have several tools at your disposal:

– Regular Substrate Vacuuming

You should vacuum your substrate regularly anyway, whether you have Detritus worms or not. Vacuuming the substrate regularly will remove fish waste, clean excess food, and clean algae overgrowth. It’s a necessary procedure, especially if you have substrates with large granules, like gravel, crushed coral, limestone, or marble.

These types of substrates will allow food leftovers and fish waste to infiltrate inside the substrate and decay, releasing ammonia and other harmful chemicals. And you won’t notice the accumulation of dirty unless you vacuum the substrate.

The same procedure will eliminate Detritus worms and destroy their colonies. It is the first method of defense against a Detritus infestation since the substrate is their preferred spawning ground.

– Regular Water Changes

Water changes are also necessary in all fish tanks, no matter whether you have a filter or not. The filter will improve oxygenation, create surface agitation, and control the ammonia levels in the tank, but you can’t rely on them long-term. Eventually, you will need to perform a water change, especially if your tank holds more fish than it should.

Regular water changes will keep the water fresh and clean, making the environment unbearable for Detritus. The frequency of the water changes will depend on aspects like tank size, how much waste the fish produce, how many fish you have, etc.

I recommend weekly water changes, changing no more than 10-15% of the total water volume on each occasion.

– Improve Aquarium Filtration

A good, reliable filtering system is necessary in any tank. The filter will boost the water’s oxygenation, create water currents to help fish breathe better, and reduce the impact of ammonia. The same filtering system will keep the water clean by removing excess debris and sucking in food residues before reaching the substrate.

This will starve the Detritus worms or, at least, render the environment unfit for a large colony. Having a filter is essential for community tanks that require multiple feedings per day, potentially leading to excess food residues.

If your current filtering system isn’t powerful enough, consider an upgrade. Just make sure you don’t go overboard with it. An overly powerful filter may suck in the fish and destroy the live plants and tank decorations. Not to mention, many fish species aren’t fond of excessive water currents, guppies being the most notable one.

– Reduce Fish Feeding

Overfeeding is a major problem with most tank owners. The tendency to overfeed the fish stems from the fish’s appetite. People don’t realize that fish will easily overeat, just like pretty much every creature going from scarcity to opulence.

Overeating will create fish a lot of problems, including digestive issues and constipation, and that’s not all. It will also lead to excess fish waste and food residues sinking to the substrate. These will feed the growing colony of Detritus worms, causing it to flourish fast.

To prevent that, you should only feed your fish moderately throughout the day. Some fish will only eat once or twice per day, like guppies, while others are fine with eating every other day. The truth is that most fish can go several days up to a week without food. We’re talking about healthy adult fish.

This is an evolutionary adaptation to their natural environment, where food is rather scarce and competition can get steamy. I suggest feeding your fish once per day. That should be enough to provide them with proper nutrients without overburdening their system with excess food.

You should only feed the fish twice per day in case you have a large community tank, and you want to make sure everybody gets to eat.

– Quarantine New Plants

You never know where those plants have been to. They might be infested with various parasites or can harbor parasite eggs that could infest your fish. They will also harbor Detritus larvae.

You should always quarantine the new plants for several hours before adding them to your tank. This will eliminate the risk of infecting your tank with Detritus and ensure your fish’s healthy and stable environment. It will also help to distinguish between dead or dying plants and viable ones, ready for use.

– Use Hydrogen Peroxide

I should begin by saying that Hydrogen Peroxide is by no means a benign chemical. It makes for quite an extreme method of tackling the Detritus worms, which is why most people only use it in cases of severe infestation. Hydrogen Peroxide won’t hurt your plants, but it can hurt your fish.

For this reason, you should remove any fish, shrimp, snails, or any other aquatic creature you’d like to keep beforehand. I also suggest consulting a tank professional before using Hydrogen Peroxide. An expert can guide you on how to use the chemical and reintroduce your fish safely after you’ve removed all traces of the substance.

Are Detritus Worms Bad for Fish Tanks?

Not by default. Detritus worms are actually beneficial for aquariums, thanks to their eating behavior. These creatures are scavengers and will primarily feed on dead plant matter and decomposing fish. Noticing Detritus worms in your aquarium shouldn’t cause panic unless the infestation gets out of hand.

Seeing how Detritus worms only thrive in murky and unclean waters, a large-scale infestation suggests that the environment is no longer fit for the fish. Extremely dirty waters will affect the fish due to dangerous ammonia buildup and low oxygenation. Seeing Detritus worms floating in the water should be the last of your concerns.

To prevent that, perform regular water changes, have a filtering system in place, use an air pump, and clean the tank regularly. These measures alone will keep the Detritus worms in check and prevent them from overtaking the tank.

Do Fish Eat Detritus Worms?

Yes, they do. Almost all fish will eat Detritus worms if they encounter them in the water. After all, they are sources of protein that your fish won’t ignore.

However, you shouldn’t rely on your fish to control the population on Detritus worms. Most worms will remain hidden in the substrate, which automatically places them outside most fish’s hunting grounds. You can keep bottom-dwelling fish species to control the problem a bit better, but, ultimately, it all comes down to keeping your tank in pristine condition.

Are Detritus Worms Harmful to Fish?

No, they’re not. Detritus worms don’t bite, infect, or consume fish unless already dead. They also don’t transmit any diseases that you should be worried about. These aquatic pests are scavengers, lurking around the substrate and feeding off of dead matter, whether plant or animal-sourced.

You should only be concerned if you Detritus floating in the tank. That only happens when the Detritus infestation has grown beyond reasonable. This signals that the tank waters are in worse condition than you think, requiring you to fix the situation rapidly.

Are Detritus Worms Harmful to Humans?

No, they’re not, but that doesn’t mean you should ignore them. The Detritus worms are not harmful to humans directly, but rather indirectly. They won’t bite or infect you, which means that the Detritus worms aren’t a direct threat to humans. The danger rather comes from their environment.

If you see Detritus worms floating in the tank water, that’s a clear sign of a dirty and clean environment. Not that you needed the worms to tell you that. Unclean waters are visibly murky, with particles floating everywhere, along with dead plant matter and other residues.

The presence of the worms just strengthens that aspect. While the worms themselves won’t hurt you if you soak your hand into the tank water, other things might. Stagnant aquarium waters contain ammonia and cultures of harmful bacteria that may cause infections.

You should always maintain peak hygiene whenever you mess with the tank water, especially if it has Detritus in it.

Will Aquarium Salt Kill Detritus Worms?

The answers are rather conflicting on this topic but, after researching the aspect on various forums, I can safely say I’ve reached a conclusion. And that is that tank salt does pretty much nothing. It can be effective to counter other parasites, but not the Detritus.

I suggest avoiding using aquarium salt, medication, or any other chemical to counter the population of Detritus. You might end up causing more harm to your fish than anything else.


Detritus worms aren’t a danger to your tank but rather signal the presence of danger. An extensive Detritus infestation suggests poor water quality, along with excess fish waste, food residues, and even dead matter.

If you see Detritus worms swimming in the water, you know the situation is severe. Clean the tank, change the water, and adopt a solid maintenance routine in the long run, which will, by itself, control the Detritus pretty effectively.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
Questions and Answers

How do these worms multiply? I notice little things that resemble jellyfish on tops of plants.

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