I am wondering if there is any accurate way to determine how much space any particular fish needs. I have heard things like 1 gallon per inch of fish, but this cannot be accurate as a betta (2.25 inches) should have 5+ gallons and something like a Ram cichlid (2-3 inches) should have 20+ gallons. Are there any somewhat accurate ways of determining the space a fish needs based off of some aspect of the fish (like length)?

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    howmanyfish.com Commented Oct 19, 2020 at 15:15
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    @trondhansen that seems to be somewhat inaccurate, as it relies purely on surface area. A tank with 800 square inches of surface area that is 1 inch deep compared one that is 30 inches deep can hold a very different number of fish.
    – Jacob B
    Commented Oct 22, 2020 at 5:23
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    the most important factor for how many fish you can have in a tank is the surface area,this means you can have the same number of fish in your 1 inch deep tank as you can in the 30 inch deep tank,(the water in the shallow tank will get contaminated in a shorter time but this can be managed by water changes).ratemyfishtank.com/blog/properly-aerating-your-aquarium Commented Oct 22, 2020 at 10:56
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    The fish do like a certain level of water most. You can see it on their snout: when it looks upside, they will stay the most time near the surface, when it looks downside, then they will stay on the ground the most time. So this fish has no thinking about how high the water level is, they want to have space in the same level to swim and feel not caged Commented Oct 22, 2020 at 13:50


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