Fish get more active with more flow. I run a Aquatop cf500 on my 40b. It's factory rating is 525 gph, and up to 175g tanks, and yet if you look in the tank all of the feeders move around as if they are in a bowl, and my puffer has gotten super active, and really friendly towards me since I installed the filter.
I run two of these on my 75g. I think it may be a little much esp. With it being a planted tank, but I just planted new plants that will get use to the flow. The fish on the other hand are super active as well.