Aquatop circulation pumps create important water movement for both salt and fresh water tanks. All Aquatop circulation pumps attach to the aquarium wall with a secure suction cup and have a pivoting ball joint that allows for a wide range of motion.
Rivers to Reef says: There is no real rule of thumb for circulation pump size. If you have a saltwater tank, typically you are going to be aiming for a water flow of between 7 and 15 times the volume of your tank. If you have a FOWLR tank then you can probably have less flow, if you have an SPS dominant tank you probably want to have more. If you find that your flow is lacking, adding more pumps is the way to go, do not try and just upgrade your current pump.