Selecting a Pump:
For healthy filtration the pumps needs to be strong enough to circulate the total volume of water through the filter once per one or two hours. The minimum should be 500 gph per hour. There are many things to consider when choosing a pump:
Pumps incur resistance as they move water from the pond to the filter, waterfall or water feature. The water a pump circulates is reduced the farther and higher the pump has to push the water. Gravity create pressure which decreases the pumps output. Pumps are rated for the amount of water they can pump without resistance. A 1000 gph pump is usually at 1000 gallons of water per hour without a pipe connected. (Refer to individual pump flow charts for detailed information)
Friction diminishes pump performance as the water travels through plumbing. Every 10′ of horizontal travel through pipe is equal to 1′ of vertical head lift. Avoid too many curves or sharp angles in the tubing. Do not undersize the pipe or tubing that you connect to your pump and filter otherwise the flow will be reduced. Refer to our friction loss and our Pipe chart below.
Gallons per hour, not the diameter of the pumps discharge is the way to determine proper pipe size. Many people undersize there plumbing and cheat themselves of the optimum pump flow. Proper pipe size is determined by the maximum GPH capacity of the pump.
Some people will opt for two pumps when they have a waterfall. First; when you choose a pump for a waterfall you will want to go with this rule of thumb: 1200 gph per foot of width. There are a few differences in which this will vary. (See Waterfall width chart below) You will also want to consider the proper amount of flow required for your filtration system and this is where the second pump comes in handy. Lets say you have a 3′ wide waterfall and your pond has a volume of 1000 gallons of water. Well rule of thumb says that you need 3600 gph for your waterfall but just 500 – 1000 gph for proper filtration. You would install a smaller pump for filtration and a larger pump for your waterfall. This is also handy if one of the pumps should breakdown, you will have a spare. Also keep in mind this flow is just a starting point. Personal preference may warrant a larger flow rate. I personally like to go with 2400 gph per foot of waterfall width as it will give a thick waterfall flow.
Below or Above the water level:
99% of the pumps that we sell must be located below the pond surface level. This is called “Flooded Suction”. Gravity forces the water into the pump and therefore creating a prime. We do have external pumps that are either self-priming or require a priming pot or leaf trap to be operated above the water level.
From the gentle trickle of the smallest fountain to the heart-pounding roar of the largest waterfall, the success of any water feature is dependent upon the pump used in its construction. Many different types of pumps exist to help the pond industry professional create the perfect effect for each of their installations. With the advancement of technologies in pump manufacturing, today’s professional pond installer has an ever-increasing arsenal of pump choices to help create the ultimate water feature. Among the most popular pumps today are submersible magnetic drives, direct drives, and the newer hybrid magnetic asynchronous pumps. This article will look at the similarities and the differences between these three pump types and will look at the benefits and drawbacks of each. New advancements and marketing trends for these pumps will also be discussed to better prepare the industry professional for meeting consumer wants and needs.