How many fish can I keep in my aquarium?
If you're just starting out with aquarium keeping, one of the first questions you'll probably have is: "How many fish can I keep in my aquarium?" The answer, however, isn't as simple as it seems. Several factors play a role. Let's discover together how many fish your aquarium can hold!
The number of fish you can keep in an aquarium depends heavily on the species and the size of the tank. 0.5 cm of fish per liter is usually the norm. Less is always better than more.
(this is way too much for such a small aquarium)
How many fish can I keep per liter?
When determining the number of fish in your aquarium, the general guideline is about 0.5 cm of fish per liter of water . So, if you have a 100-liter aquarium, you could have about 50 cm of fish . This sounds simple, but there are more factors to consider!
Besides the size and species of the fish, filtration also plays a major role. A well-functioning filter ensures that waste products are removed more quickly, allowing you to keep more fish. The layout of your aquarium is also crucial. If you have a lot of hardscape, such as wood and stone, that will take up liters of water, meaning you can keep fewer fish.
For more hardscape inspiration, check out our aquarium wood or aquarium stones . Want us to create a hardscape for you? You can with our aquarium service >
An alternative calculation method is to consider the number of fish you can comfortably accommodate in your aquarium, rather than just the centimeters. Consider the following example:
- Start with 1 fish per 5 litres and slowly add more, depending on how your system adapts.
- Observe your fish's behavior; active fish require more space.
- Choose smaller fish if you want to combine several species.
- Always stick to the minimum number for the species you are adding.
How many fish can you keep in an aquarium on average?
So, on average, the rule of 1 cm of fish per liter of water applies, but that's just a guideline. This number can vary depending on the combination of fish, their size, and the setup of your aquarium. Below is a table to give you an idea of what to expect:
| Aquarium Capacity (liter) | Number of fish (cm total) | Example of fish combinations |
|---|---|---|
| 60 | 30 | 10 guppies, 3 corydoras and 6 mollys |
| 150 | 75 | A school of 20 neon tetras, 4 moonfish and 4 bottom fish |
| 250 | 125 | 6 moonfish, a 40 school of neon tetras, and 8 bottom fish |
Please note: This table is just a guideline. You may be able to keep slightly more or fewer fish, depending on the conditions in your aquarium! And if you have any doubts, feel free to send me a WhatsApp message! 📲
It may also depend on the type of fish
Now that we've discussed the number of fish and the number of liters per aquarium, let's look at the fish species. Not all fish contribute the same amount to your tank! A plecostemus, known for its voracious appetite and waste production, will have a much greater impact in your tank than a cute little group of shrimp that cause almost no pollution.
For example, a plecostemus can produce a lot of mulm and requires consistent water parameters. If you have this fish, you should consider adding additional filtration to maintain water quality. On the other hand, a group of Endler guppies are much less demanding and place little strain on the system. This is why it's important to choose your fish carefully, considering their needs and the available space in your aquarium.
Some other examples you can consider:
- Fish like guppies or neon tetras: These are perfect for smaller aquariums and can live well in groups.
- Expert fish such as discus or cichlids: Have stricter requirements regarding water quality and space, so keep this in mind!
Conclusion
In short, the question "how many fish can I keep in my aquarium?" isn't a simple one. The number depends on factors such as the size of your aquarium, the filtration, the decor, and, of course, the species you choose. It's always a good idea to start with a moderate number and gradually build up your aquarium.
Do you have specific questions or are you unsure about a particular fish? Feel free to send me a WhatsApp message for personalized advice! 👍
