I have a 55 gallon planted aquarium and I've been running a marineland emperor 400. I've had both the filter and tank for close to two years. For the past few months or so the flow has dropped from powerful to a trickle. I have no clue why it's done this. I've already tried taking it apart to see if it was clogged or something, but it still isn't working right. This has also caused a lot of dead spots in my tank. At the moment I have it working along with my old tetra whisper 60. The emperor for waste and the whisper for flow. I've had both on before, but took the whisper off, because I didn't like the look. It seems to help although. When both are running there's no build up of film on the surface and most of the dead spots receive flow. The fish also seem more active with both filters. I only have 7 diamond tetras, 5 slivertip tetra( had 13 but they passed for unknown a reason) 3 otos, and a pair of kribs. I want a canister filter, but I'm still saving. I was thinking of maybe adding a powerhead will help? I don't wanted spend money on a new filter.