Any container 30 inches long 13 inches wide and 13 inches high has a volume of 22 gallons
Volume: 30*15*12 = 5,400 cubic feet
2304 Inches cubed
168.311 US gallons.
= 93.09 gallons (US) = 77.51 gallons (imperial)
Approximately 201 gallons.
im no expert but it sounds like 125 For the size in gallons for a rectangular aquarium, the formula is: (Length x Width x Height) divided by 231
Assuming it is a rectangle, 42.077 US gallons
22x20x13= 5720 cu inches assuming you want in gallons it is 24.76 gallons
A bit less than 75 US gallons.
3,465
Volume = 29 x 21 x 9 = 5,481 cubic inches = 23.73 gallons (rounded)
Koi are pond fish and grow to over 24 inches or so when adult. It is unlikely they will breed for you in a small aquarium. (It is also unlikely they will live long in a small (under 75 gallons) aquarium)