We are reader supported. When you purchase through links on our site, we may earn an affiliate commission. Also, as an Amazon affiliate, we earn from qualifying purchases.
People keep goldfish alive and healthy inside their homes for several reasons, and in modern times a quite popular reason is these pet owners believe these small golden fish clean the tank as they eat. Fact or fiction?
Goldfish do not clean their own tank entirely, but they may help a little by consuming small portions of waste that accumulates in their typically small aquariums. In all, goldfish can assist with cleaning maintenance duties, if the tank is small, but alone they cannot keep the tank clean.
In medium- to large sized aquariums, goldfish do not eat enough algae to make much of a difference.
There are many species of other types of sea- and freshwater life that can make more of an impact in keeping your fish tank clean; some are listed below.
If you want help keeping a goldfish tank clean, think about freshwater snails or leeches. Snails in particular eat leftover food flakes, organic debris, algae, and more, especially in the substrate material (pebbles, sand, crushed coral, etc.) at the very bottom where such debris tends to settle.
Most anyone who has raised a goldfish in a small (or relatively small glass bowl) inside your home knows that this species of water life is rather well-known for being messy. That’s kind of true, and kind of untrue.
A goldfish can seem messy to an owner over time ~ because goldfish grow, but their home environment mostly does not.
That is, they get way too big for their little glass bowl, and usually get no help from other aquatic life in eating all the algae and excesses.
Healthy, aged goldfish can grow up to a foot long! As they grow, always consider moving into a bigger aquarium.
Goldfish that grow large eat more and their body disposes more. Because aquarium fish rarely get to all the fish flakes we sprinkle in as food, it accumulates on the bottom where the fish can no longer get to it.
This material continues to break down into tiny particles that are useless to the fish, but when it accumulates it can create the appearance of a cloudy goldfish tank.
First off, algae is not the end of the world inside a fish tank. Seeing a little algae in an aquarium indicates that the micro ecosystem in there, overall, is healthy and balanced. It’s natural. Just don’t let the green or black gooey stuff get out of control.
Goldfish will indeed ingest small amounts of algae, but in more of a snacking style. They prefer fish food (the dry flakes we pepper into tanks), or small insects.
Second, it’s fairly easy to know when to change the water and clean the tank. It’s all in how well you can see your goldfish.
Goldfish bowls are prone to cloudy water due to bacterial blooms, which thrive in the warmer fresh water usually held in indoor fish tanks. Add to that all the debris mentioned above that freshwater snails love to munch on, and you can see the potential for things to get in the way of seeing your fish.
It’s not necessary for the bowl to be crystal clear all the time. In fact, there is live bacteria living inside fish tanks that help keep up the nitrogen cycle that keeps ammonia levels down.
But if the tank looks pretty cloudy, like someone spilled milk in there, it’s probably wise to clean it and maybe swap out the water.
Lastly, but perhaps most importantly, don’t simply use tap water to fill a goldfish tank (or small aquarium for any fish, for that matter). All kinds of chemicals are added to the water we humans drink, namely chlorine, which is not so friendly to small fish.
It doesn’t mean you have to purchase distilled water, or any other kind of specially treated water, Just find and buy a water conditioner, which neutralizes the chlorine making it fish safe.
Many parents have heard the complaints about how a goldfish pet died within a week or so. This is typically from the water, which either was not changed enough, or was not changed correctly.
First off, as stated above, do not just dump common household tap water into the tank. (See above for the dangers of chlorine).
Secondly, do not replace all of the water in a goldfish bowl at once. This is almost certain to kill your pet. You want to leave about 40% of the old where it is. You should only replace more than half of a fish tank’s water at a time.
This cleans enough waste from the bowl, while still mixing in natural fish environment elements that contribute to the overall balance in the small ecosystem.
Finally, when you change the fish tank water, do it slowly. That is, carefully let your pet acclimate to the new environment.
To do this, just simply add new dechlorinated water a little at a time, or very slowly, while the goldfish is in the water in the tank. Do not change the water entirely and then toss a goldfish in!
Question: What other types of water life can help keep my aquarium clean?
Answer: Many aquarium enthusiasts are familiar with amano shrimp, the tiny lobster-looking thing walking along the substrate. These invertebrates have tiny claws that reach into cracks and crevices other fish cannot reach ~ therefore keeping the substrate fresh from rotting waste. Other good fish tank cleaners can include flagfish, eartheaters, and the corydoras, known as the cory catfish.
Q.: How long do goldfish live?
A.: Believe it or not, up to 15 years! The lifespan of a single goldfish is said to be about 10 to 15 years ~ if properly cared for. Some species could live much longer. However, few live that long due to improper care for where they live ~ their aquarium ecosystem.