TIDAL all the way baby... self-starting and very quiet. Sicce makes the best submersible pumps in the world.Very easy to maintain and hotrod with your favorite filter and media components. They provide great water flow. I switched from running two Fluvals to one Tidal and one Hygger Sponge filter in my 55-gallon tanks. I own 2 Tidal-75...did I mention they are self-priming?!!! My Lemon Pleco pair had babies. Some ended up in the filter and because of the design, they did not go through the pump and they all lived.( I have a prefilter sponge). Some made it through the surface skimmer another great feature and that may affect your choice if it's a breeding tank or you host very small fishies.im stuck between the tidal series, aquaclear, and marineland biowheel filters ?!?!? idk which one to get ahhh!!!