I have a 65 gallon planted aquarium with an Emperor 400 HOB filter. My tank is tall, rather than wide. I saw an ad for a Fluval FX5 that interested me in switching to a canister filter. I asked Hagen for a recommendation and they stated that the filter would cause too much flow for my setup. They suggeasted a Fluval 305 or 405. The filter manual indicates that you can throttle the FX5 flow without damage to the pump. I understand that flow is less than adverstised for HOB's, but the Emeperor rated flow is 400 gph while the 405 is 225 gph. Forum posts routinely indicate that you can never have too much filtration. What's the opinion here regarding the FX5 for my setup? The FX5 is rated at 924 gph.