In comparison, a long tank that measures 24” x 12” x 12” has a surface area of 2.00sq ft. Q: Why do some people use stocking densities based on surface-area?Ī: The principle that ample surface area is essential for good gaseous exchange and, therefore, good oxygen saturation in the water is often used to calculate stocking densities.Įssentially, that calculation is based on the assumption that if you have a tank with a small surface area, you can keep less fish than you can in a tank with a greater surface area.įor example, a tall tank measuring 12” x 12” x 24” has a surface area of just 1.00sq ft. However, that’s best left to industry experts who know exactly what they’re doing. In aquaculture, fish densities are often many times higher than you would have in a home 29-gallon aquarium setting. However, I don’t recommend exceeding the suggested stocking density, as that could cause problems with water quality. Most shoaling species need plenty of open water swimming space to thrive, and territorial fish also need extra room to adopt and defend a territory.Ī: Basically, yes. Aggressive species generally require more swimming space so that confrontations with their tank mates can be avoided. Specific fish species can be exceptions to the calculator rule, depending on their individual requirements and preferences.įor example, species such as goldfish and Oscars produce a large amount of waste and are very oxygen-hungry, so they need more water volume than the calculation suggests. You must also install an adequate filtration system and monitor the water chemistry in the tank. So, be prepared to carry out partial water changes every week, vacuum the aquarium substrate to remove waste and uneaten food, and keep up to speed with filter media maintenance and replacement. Regardless of the size of your fish tank, if you fail to maintain it correctly, you shouldn’t be keeping any fish at all! The stocking calculator makes the assumption that the aquarium is correctly maintained. When calculating how many fish your tank will hold, always use the adult size of the fish for the calculation. When you buy your fish, remember that most of the little creatures you buy in your local fish store are juveniles that may grow to double that size or more at maturity. Also, coldwater fish need less surface area than marine species. Slim-bodied fish such as danios and tetras typically need less oxygen than fatter fish such as Oscars and goldfish.Ĭalculators reflect that by allowing for the two extremes, providing more space for full-bodied fish based on the surface area of the tank. Note that using air stones to agitate the water surface doesn’t mean you can keep more fish. That’s because, in the narrow tank, less surface area is in contact with the air. That works best because the surface area of the aquarium determines the amount of dissolved oxygen there will be in the water, and it’s that which determines how many fish you can keep.įor example, a tall, narrow fish tank can’t support as many fish as a regular rectangular tank, even though the water volume of both tanks is the same. Stocking calculators use the surface area of your aquarium to work out what the stock levels should be rather than using gallons.
Simply insert the details about your fish tank shape and dimensions, together with information about the fish species you plan on keeping, and the calculator will tell you how many fish you can fit in your aquarium. The best way to work out how many fish you can keep in your tank is to use an aquarium stocking calculator. Other fish need lots of open swimming space, while some produce a vast amount of waste that the filter system in an overcrowded tank can’t cope with. The traditional method for working out how many fish you can keep in your fish tank is “one inch of fish per one gallon of water.” However, that method is flawed, as it doesn’t take into account the requirements and behaviors of individual fish species.įor example, some fish are highly territorial and won’t tolerate a crowded tank with limited space in which to establish a territory.