saltwater and freshwater fish newbie Question

Discussion in 'Freshwater Aquariums' started by ferretfish, Aug 20, 2011.

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  1. ferretfish

    ferretfish Sea Dragon

    Aug 5, 2011
    why in freshwater can you keep a 12" texas cichlid happy in a 50 gallon tank but why cant you keep a 7" rabbit fish or a 8" yellow tang happy in a fifty gallon tank. just curosity
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  3. Eyelash Blennie

    May 17, 2011
    Well, a 12 inch fish shouldn;t be in a 50 gal. In fresh water is has to do with swimming room (mostly ability to easily turn around). In Marine habitats it the bio load is even more important. Often times with less swimming room (boredom) the fish resort to nipping each other/corals. This can get quite costly in lives and expense!
  4. Mr. Bill

    Mr. Bill Native Floridian

    May 28, 2011
    To add to Toms post, SW can't hold nearly as much dissolved oxygen as FW, and bigger fish absorb a lot of DO. Also, SW fish have to drink a lot more water and pee way more than their FW counterparts to maintain body fluid levels and keep the excess salt flushed out. That's just a couple more reasons why there is such a difference between FW and SW in the number and size of fish we can keep in given size tank.

    You may also notice that the minimum tank size can vary between 2 species of the same adult size; that will depend a lot on if it's an active swimmer that requires a lot of open space, or a sand or rock skipper.