How many gallons is a tank that is 30 inches long x 12 inches wide x 18 inches tall?

Answer 1

30" x12" x18" = 6480 cu ins. 231 cu ins = 1 gallon US. The tank filled to the brim will hold 28.05 US Gallons approx. When in use the tank will actually hold (internal measurements) 29.5" x 11.5" x17". = 5767.25 cu ins which is 24.97 US Gallons.

The basic rules for keeping fish successfully are :- 1 inch of fish needs a minimum of 1 gallon of water. :- Every tank needs a permanently running cycled filter. :- Every tank need at least 50% of its water changed every week. Follow and keep to the above rules and your fish stand a chance of survival. Fail to keep them and I can guarantee that your fish will be constantly getting ill and maybe dying.