Optimizing the stocking of your fish tank as much as possible is as much an art as it is a science. Generally speaking, its purpose is to determine the maximum number of fish a fish tank can hold without becoming too crowded. Several issues need to be considered in determining the upper limit. But with a little research, you can figure out the maximum number of fish you can keep in a fish tank.
Determine the Volume of the Fish Tank
Measure the fish tank. The standard unit for fish tank volume is liters. At the beginning of your purchase, you should find out how big the fish tank is. But if you don’t know or don’t remember, you can calculate it mathematically.
- To find out how many liters a fish tank contains, you need to measure its length, width, and height in centimeters, multiply the three together, and divide by 1,000. This number is only an approximation, and the actual capacity will be smaller due to factors such as glass thickness, fish tank bottom, and decorations.
Maintain proper water levels. Keep the water level at the right height to accurately calculate how many fish it can hold. If the water level is too low, the number of fish the fish tank can hold will decrease. Generally speaking, you should keep the water level about two to three centimeters above the rim of your fish tank’s filter.
- Remember, the volume taken up by an object submerged in water also matters. If a fish tank has a lot of decorations in it, it won’t hold as many fish as a similarly sized tank with fewer decorations.
The general rule is to keep one centimeter of fish per liter of water. However, this principle does not always apply. A 10-liter fish tank cannot support 10-centimeter fish.
- This principle is most applicable to small social fish, such as fat carp, rainbow fish, moonfish, etc.
- When determining what size tank your fish needs, learn more about the fish.
Use the surface area principle. Since gas exchange occurs at the surface of the water, and this process helps fish survive, be sure to consider this factor when adding fish to the tank. A larger surface area means more oxygen exchange within the tank which is beneficial to the fish.
- With the same surface area, although a deeper fish tank can hold more water, it may not be able to raise more fish than a shallow fish tank.
- This is a better rule of thumb when judging how many fish to keep in a tank because it takes into account not only the available space in the tank but also the oxygen needs of the fish.
Decide Which Types of Fish to Keep Together
Determine the type of fish you want to keep. Do you want the school to be made up of lots of small fish, or fewer large fish? If it’s the former, consider the cyprinid carp; if it’s the latter, consider the angelfish or African cichlid. Or just keep one big fish, like Oscar fish? Look around and get an idea of what fish you like, then do as much research as you can on compatibility and maximum numbers.
- Some fish are more aggressive and require more individual space, while others blend in well with larger schools of fish. Do your research before putting your fish together.
Consider the amount of fish to feed. For small social fish within 8 centimeters in length, one centimeter of fish per liter of water is a good reference principle. However, if the fish are larger, determining the number can be a little trickier. Assuming that the fish on your list is not too big for the tank and can coexist with the other fish you want to keep, you can start by trying one centimeter of fish per three liters of water and observe the situation in the tank.
- You should have a balanced amount of fish in the top, middle, and bottom layers of your tank. This depends on the depth at which the fish you choose usually likes to swim. For example, sucker fish usually live on the bottom of the water, while ax fish prefer to stay near the surface.
Research the specific needs of your fish. If you want to keep any fish together in a fish tank, be sure to understand their characteristics. Many fish have different requirements for the living environment in the fish tank.
- Some fish cause a mess in the tank, some are very aggressive, and some are nocturnal. Gather information from a variety of sources to understand these differences.
Understand your fish’s oxygen needs. Different species of fish have different requirements for oxygen. Plump fish such as goldfish consume more oxygen than thin fish such as fatty carp. A fish tank with mainly large fish requires more oxygen than a fish tank with mainly small fish, so the former requires more space.
- To oxygenate the water you can use a fish tank aerator and filter.
- The number of fish fed must take into account the size or weight of the fish in the tank when they grow up so that the oxygen needs of the fish during growth can be fully met. So if the fish you buy are still juvenile, when figuring out how many fish to keep in your tank, be sure to consider how big they will get and how much oxygen the adult-sized fish will need.
Fish Tank Maintenance
Solve filtering issues. If the fish are causing a mess in the tank or there are a lot of fish, you will need to use more adequate filtration, but in any case, the bigger the filter, the better. The filtration system helps to keep the fish tank clean and the water pure, allowing the fish in the tank to thrive.
- Fish such as hatchet fish and Thai bettas require slower filters, while others such as loaches, goldfish, and Oscar fish require powerful filters.
Maintain a regular feeding schedule. Excessive feeding of fish food can lead to turbid water quality and make the fish tank difficult to maintain. Over time, this will reduce the number of fish that can be safely fed in the tank.
- Generally speaking, fish should eat one portion of food every day that is about the size of their own eyes. You can feed this amount of fish food twice a day, but it has been proven that fish are generally healthier when fed only once a day.
- Feeding too much fish food can also lead to high ammonia and nitrate levels, fish illness, indigestion, and turbid water quality.
Clean your fish tank frequently. A dirty fish tank can cause a lot of trouble for your fish. It can cause illness, discomfort, and even fish death. The dirtier the fish tank, the fewer fish it will hold due to lack of oxygen and filtration issues. Even with a good filtration system, you should generally clean your fish tank once a week.
- Try the method described in the article How to Clean a Fish Tank.
Tips
- Fish will not grow to the size of a fish tank, so don’t doubt it when you hear the phrase “A 2cm special-shaped fish can grow to 60cm”!
- Before looking for fish to fill your tank, make a list and research the fish you want to put in your tank.
- Overcrowding can lead to stunted fish growth, aggressiveness, disease, and poor water quality. You should avoid this problem at all costs, and even if you see it in a pet store, don’t think it’s okay to do so.
- Some fish excrete more waste than others, which can affect the maximum number of fish that can be fed in the tank.
- Many fish will grow to very large sizes, so if you don’t know anything about a particular fish, don’t buy it.