I really like the fluval FX5 from what I Have used it on it seems well built and great filtration. not to mention the nice lil microchip in there that wont let you burn out the motor. I never replaced the filter pads unless it was polyfiber or another fine filter pad, everything else I just rinse until it rinses clear. Use mostly carbon and some bioballs/LRR in the baskets and havent had any problems. Just have to remember to clean it once a month or so w/ your partials. It is recommended however to clean your sponges more frequently if you notice a nitrate problem.