There is a very basic “Rule of Thumb” that suggests 10x turnover rates…
 
This is a very good “Rule of Thumb” but with all such generalized suggestions, it overlooks any and every possible detail of your particular tank. For a 330 gallon tank I highly suggest you design a more customized filtration approach that ignores “Rule of Thumb” type information and considers literal details of your particular situation…
 
Now if it were only that easy…
 
DawnMarie definitely has the right approach. Tell us about the tank you want…
 
In addition to the questions above, how much and what type of décor do you plan on using? Solid objects reduce water flow and decorations provide crevices for waste to get lodged in. So a bare bottomed tank with no décor can get away with a lot less water movement than a fully decorated tank… but since “beneficial bacteria” grows on surfaces, a tank full of décor has less of a ‘need’ for bio media…
 
So I suggest you plan the tank from fish, to décor, to water movement, to filtration… not the other way around…