Desired Flow Rate
The optimum tank "turnover rate" is approximately 3 to 4 times per hour for saltwater fish-only tanks, 7 to 8 times per hour for saltwater reef tanks and 2 to 3 times for freshwater tanks. To approximate a aquarium pump's flow rate in a closed system, subtract 25% from the pump's maximum rate flow to compensate for filter and plumbing restrictions. For example: using the multiple of 4 times per hour, a pump with a maximum flow rate of 800 Litres per hour (lph) would be appropriate for a saltwater fish-only tank of about 150 Litres ((800 *.75)/4)=150).

If you want to be more exact about the degree to which the filter and plumbing will compromise the flow of the pump, you can calculate the head pressure (the calculation is provided below) and refer to the charts provided for most pumps.

Head Pressure
Generally, the head pressure is the distance from the inlet of the aquarium pump to the discharge point in the display tank. As the head pressure increases the lph will decrease. Along with the distance from the inlet of the aquarium pump to the discharge point in the display tank, a number of factors effect head pressure: Each 90-degree bend in the plumbing will add about one foot of head due to friction. As a result of friction, each 3 metres horizontal run of pipe will add a 300mm of head pressure Any time a pump discharge is shunted off, perhaps to a protein skimmer, this will also rob the display tank of flow

Aqua One 101F Internal Power Filter
Suitable for fresh and saltwater aquariums.
Completely submersible.
Quiet and efficient. Includes foam, adapters and venturi.
400 Litres per hour.

Aqua One SR9500 Double Air Pump
Aqua one double outlet air pump with hi-med-low output switch.
Air output 9500 C.C. per minute (510L per hour).