Fluval are good filters, but they have small filter sponges that clog up quickly, meaning more work to keep them clean. In fact most internal filters have small filter sponges and big pumps, which is really the wrong way around. Due to this arrangement you need to get a big unit too get a reasonable size sponge, and the big units tend to blow the fish all over the tank. Some companies have been working this out but most still make big pumps with small filters.