Try to understand the meanings of the terms being used in the industry while you are planning to upgrade the pump on your fountain or you are still starting to build one.

Gallons per minute is GPM. Gallons per hour is abbreviated as GPH. These are rated depending on their height.

Head is the greatest height (vertical lift) that the pump can deliver. So, a 6 head denotes that the pump can drive water below six feet in height. Consequently, a pump is no longer effective at the height of six feet. So if your requirement is 200 gph at 72", a 300-600 gph pump should be specified. See to it that the pump curve is specified for a particular pump.

The amount of water volume pumped with regards to a specific height is called pump curve. Take for example a 500 gph pump, it can pump 500 gallons by the hour if the pipe or hose is level. If it has to be driven to a height of two feet, the rate will be reduced to only 350 gallons per hour. Make sure you know the volume (gph) of water to be pumped and the height (head) it has to be pumped before you drop by a pump dealer.

Water volume is governed by the size of the pump and the diameter of the tube or pipe. Tubing diameter is measured in two manners: by the outer diameter (od) & by the inner diameter (id). Tubing with a small diameter, contrary to popular belief, will produce only minimal water flow. The maximum flow you will get is 200 gph, give or take a few if you hook your 500 gph pump to a ½" id tube. Remember this when acquiring a pump, you have to know the tubing size that goes with it. The length of run of the tubing is another factor to consider. The longer the length of the tube is, the higher the resistance. The requirement of your pump is for a 1/2" id tube yet the length of the run is 20 ft from the pump. Compensating this can be done using ¾" id tubing will be more suitable.

Now, do you know the size of the pump that you should be getting? This will be determined by the requirements of your waterworks. For fountains, there is always a standard recommendation for this. But for waterfalls, use this formula: multiply the width of the stream or waterfall sheet by the water volume at the height level.