When selecting a pump for your spa or pool, it is important to do your homework ahead of time.
It is not always a good idea to choose a 2 HP pump just because your pool builder put a 2 HP pump on it. He may not have done his homework.
It is important to determine the desired rate of flow in GPM (gallons per minute). It is
also important to consider the flow demand of features such as spas, fountains, automatic pool cleaners, and in-floor cleaning systems. It is also important to
think about other features such as energy efficiency, ease of service and durability.
The pump must have a minimum flow rate in GPM (gallons per minute) that will allow it to move all the water through the filter within a given amount of time. The size and usage of the pool is the first item to consider in order to determine what the minimum flow rate is.
Your pool may have certain features that require more flow in order to be effective. For instance, spa jets need a certain amount of flow in order to be effective. Some automatic pool sweeps increase the flow requirements of the pump.
The plumbing of your pool is only designed to carry so much water per minute. If you exceed this amount, you will be wasting energy and can end up damaging the pump.
The pump should be properly matched to the filter. An oversized pool pump can damage the filter internals or force the water through the filter at such a high rate that the filtration is no longer effective.