It sounds as though you have reasons for "over-filtration," such as turtles, etc. So I'll just add a couple of general comments for the benefit of others reading this thread.
Filtration must be suited to the aquarium, in terms of type, media [mechanical, biological, chemical] and flow rate. Too much "filtration" is as bad as too little; neither is beneficial but may often be very detrimental.
Several factors affect filtration, and these should determine the type of filter needed. Aquarium size and fish load, not only numbers of fish but species. Live plants, again both quantity and species [slow growing filter less than fast growing].
Moving more water through the filter faster will usually result in less efficient/effective filtration because the pollutants in the water are moving through the media too fast.
Some fish species cannot manage with excessive water movement and they will be stressed and prone to health problems and likely premature death; most forest fish are in this group. The same is true in opposite, if the fish in the aquarium require water currents (Hillstream Loach for instance) this must be provided or the fish will be weakened and more prone to health issues.
A given sized tank should always be aquascaped for the specific fish to be included. And this includes the choice of filter.