I tried using the calculator and it said that this tank was 90 gallons. however it said that the maximum number of fish that i could put in it was around 50"? WTF. Did I mess up. What is going on here. I know that the rule is 1" per gallon. So what did I do wrong. I may be going to buy this aquarium in the next few days so any advice or suggestions for questions I should ask would be greatly appreciated. Thanks soooo much.