What eats Fish Poop? And how to get rid of Fish Waste

As a new fish keeper at home, you begin to wonder what eats fish poop. Do some fish eat other fish’s waste? How does fish waste look like? More importantly, how do you get rid of fish waste inside the aquarium?

This article can help you answer these and other related questions you may have in the near future. By making yourself well-equipped with fish-keeping knowledge, particularly when handling fish poop, you can take very good care of your fish pets.

Short Answer

This question may have already popped up in your head but you are too shy to ask: What eats fish poop? So, we are making things easier for you. Before you even voice this out, we are already giving you the answer to this question: No fish has ever included fish poop in their diet—not even corydoras and pleco, known as the cleanup crew.

Some say snails, but no. They eat decaying plant matter and leftover food (not rotting, okay!) or anything that fish don’t eat, but they don’t eat fish waste. Okay, you may happen to see fish try to bite fish waste, but this is not surprising because they tend to consume whatever they see floating in the aquarium. But watch a bit longer, and you will notice that they also tend to spit it out fish poop like what they do to other non-food materials that they have mistaken for food.

Long Answer

It is especially important for fish keepers at home, especially those who are just new to it, to understand fish waste. Often, this aspect is ignored when taking care of fish because some thought that fish keeping is as simple as putting fish and water in the tank. Remember, fish in the aquarium are not only meant to add beauty to your home. They are also meant to be taken care of. By learning more about fish waste, you will understand more about this.

In this section, you will recognize what fish poop is, how it looks like, how its color varies from the food it takes, and how you will know if there is something wrong with your fish by just checking out the color of the fish waste. More importantly, you will learn how to remove fish poop in the tank (in a few easy steps!) to keep your fish healthy.

What is Fish Poop or Fish Waste?

Typical fish poop is solid that it will immediately go underneath the tank when excreted. It’s quite short or medium but not longer than the length of the body of the fish. If you see poop still hanging from the pore of the fish, do not worry because it will still drop in a minute or two.

However, if it takes longer than that, it means the fish has difficulty expelling it fully. Additionally, if you look closely and the waste seems stringy, it also suggests fish constipation. Fish are prone to it, particularly when they are fed with a pellet- or flake-based diet. This can cause serious issues like swim bladder disease and loss of appetite if not treated immediately.

How often do Fish poop?

If it is your first time to keep fish at home and set up an aquarium, you will wonder how often they poop. It is because you think that this will also determine how often you will clean the tank. Now, to answer the question: It takes a long time for fish to poop because there are times when their digestive system is packed with the food they pick up. The digestion process then takes many days to complete, especially when they took complex food.

For fish that are constantly fed, they poop once at a minimum of every 48 hours. Otherwise, the frequency is irregular and sometimes even delayed. Those that starved will not poop for a maximum of 4 days.

Where do Fish poop?

Fish poop, as well as pee, through their skin or gills. Their skin is absorptive. This is why they can poop through it. On the other hand, their gills have the ability to eliminate any waste or unnecessary material in their body; thus, helping to excrete waste. Some, however, have a pore, a small opening that is situated in the rear end of their body, and that is where they poop.

What Color is Fish Poop?

Fish waste depends on the color of what they eat. Aside from this, their poop also consists of bacteria, salt, and food particles that they could not digest.

Expect red poop if your fish keeps on eating flakes, which composed many blood worms. On the other hand, if your fish is used to eating peas every time, excreting a greenish poop should not be a surprise. Now, if the poop is dark green, then you gave the fish darker peas. If you are not used to giving food to your fish or often forget to feed them, you will see clear or something white. Pink poop, on the other hand, indicates that you feed them with shrimp or meat.

Aside from the color, fish poop also varies in texture, odor, and volume.

Is Fish Poop good for Aquarium Plants?

Yes, fish poop is good for aquarium plants. The waste may be poisonous to the fish, but for plants, it is their rich fertilizer. The water that has the fish poop from the tank goes to the hydroponics tray, where the aquarium plants grow. The aquarium plants soak up the nutrients, and in the process, the water gets purified and recycled to the aquarium.

Is Fish Poop dangerous for Aquarium Fish?

Yes, it is. When fish poop breaks down, toxic ammonia is produced. However, this becomes a harmless nitrate because of the aquarium nitrogen cycle.  But when you leave your fish tank unclean for a longer time, the nitrate concentration increases, that it subsequently weakens the fish’s immune system. When this happens, fish becomes prone to diseases.

Here you can learn more about the aquarium nitrogen cycle: How to cycle a Fish Tank.

Additionally, as fish poop accumulates at the bottom of the aquarium, the rotting organic waste also piles up. The aquarium nitrogen cycle can no longer maintain the level of ammonia, which consequently increases. Because it becomes poisonous, it can kill your fish. The high nitrate concentration will also result in algae growth and a sudden decrease in the water’s PH level, which can shock and eventually kill fish.

This is why it is very important to clean the aquarium regularly, particularly eliminate fish poop.

Tutorial: How to remove Fish Poop from a Fish Tank

Here are the steps on how to eliminate fish waste from the fish tank:

Step 1: Decide if you will clean the fish tank with or without the fish.

The first thing you need to do is to decide if you will clean the tank with or without the fish. Will you put the fish in a holding tank, or will you start the vacuum without getting the fish out of the tank? It is, however, advised not to remove the fish (unless it is needed) to avoid stressing them and eventually making them sick. Make sure, however, that you do not put any harmful chemicals into the tank. But if it is really important to have them removed, do it gently using a net. Place them in a large pail or container. Fill it up with some of the original tank water.

Step 2: Remove decorations and unplug equipment.

Before draining the water inside the aquarium (and moving the fish, if you choose to), make sure that you unplug and take out all the decorations, like artificial plants and equipment, including pumps, filters, and heaters. Clean these only after you are done with the fish tank but see to it that when it’s time for you to clean the filter, practice extra caution not to get rid of the healthy bacteria.  To wash the dirt off the decorations, use warm, clean water.

Step 3: Vacuum the substrate.

After you have removed all the decorations and equipment, start vacuuming the substrate. This process eliminates all the small particulates, such as leftover food, fish poop, and dead plan materials, without moving the substrate. You may use a typical gravel siphon kit to do this.

Do you have sand in your aquarium? No worries. You can use a hose or turkey buster. If not, you can just continue using your vacuum. To start, stir the sand until the very bottom using a net or your hand. You’ll notice that the water becomes a little hazy or cloudy. Let the water clear up and begin siphoning poop, plant debris, or other deposits from the surface of the sand.

Here you will learn which vacuum cleaner is the best for your aquarium: Best Aquarium Vacuum Cleaner & Fillers.

Step 4: Clean the decorations and the equipment.

Before you place everything back to the fish tank after removing fish poop and other debris from the tank, ensure that you have also cleaned all the decorations and the equipment.

At first, you’ll find the process difficult—even nerve-wracking. Well, it’s expected because it is your first time. But as you do these steps regularly, you’ll find it easy.

Conclusion – What eats Fish Poop?

What eats fish poop? Definitely, no fish eats fish poop. This is why you have to make sure that you do not allow it to accumulate inside the fish tank. If it does, the ammonia and nitrate levels will increase and subsequently become harmful to the fish. Make your fish-keeping journey a happier one. Discover more about fish poop in this guide.


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