Filter For 35 Gallon?

[Gurglar]

I know that the filter needs to filter the amount of water in the tank about 3-4 times an hour but I was just wondering if one hang on filter would be enough for the 35 gallon or should I get 2 smaller ones? If 2 is needed do I put one at each side of the tank?

 

[dogfood]

Get the Emperor 400 HOB. It has two BioWheels, adjustible flow control and adjustible spray bars, removable media baskets and is good for up to 80 gallon tanks. It's cheap too about $40 at some places. Try to find the new revision with the window indicaters and single button flow suppressor.