Fresh Water
Volume: 2 gallons absolute minimum, some say 5 gallons minimum. Larger is easier because it takes longer for pollutants to build up.
pH: 6.0-8.0 (roughly neutral)
Temperature: 76-86 F (78-86 preferred) Being tropical, the high side of the range is more suitable.
Redfish are fresh water
No. Bettas are freshwater fish. Seahorses are saltwater.
Because saltwater fish can only breathe in saltwater (as in the ocean) and freshwater fish can only breathe in freshwater (as in tap water.)
There are freshwater drum, and saltwater drum species.
saltwater
They are freshwater fish.
No; clownfish are marine (saltwater) whereas fighting fish/betta's are freshwater fish. They cannot be placed into the same type of water or aquarium.
A saltwater fish tank can be half freshwater and all of the saltwater fish will live but not for very long.
saltwater
They are freshwater fish.
Certain freshwater fish can survive saltwater conditions; examples are black mollies, mono's and scats. All of these fish aren't truly freshwater or saltwater, they are Brackish. Brackish is between freshwater and saltwater, and so these fish are highly adaptable.
They are Saltwater fish.