Answer:
4 gallons.
Explanation:
You need to gallons for every 3 inch fish. If you do 4 plus 2 (the length of your fishes) you get 6. 6 divided by 3 is 2. So, you have to 3 inches. You need 2 gallons for every 3 inches. 2 times 2 is 4. Therefore, you need 4 gallons of water.