Every person and every set up will differ on what is "enough"...
But as a basic idea most people will aim to turn the tanks volume over somewhere between 6 & 10 times per hour... your filters are rated to turn your tank over 7.333 times per hour...
Then there is the arguement of "does this mean rated turnover or actual turnover"... and then we drag it out forever
But the simple answer is you have a great start on your filtration with the two filters you have. I would suggest you move forward with that and down the road if you decide you want a little something extra, add it.