Helpful Tips For Selecting a Pump

In selecting a pump, you will find there is a wide variety of pumps suitable for your particular application. The key to picking an ideal pump is to think through all requirementsto efficiently perform the necessary work.

Information Needed To Expertly Choose The Best Pump For Your Application.

  1. The two things you need to determine are;
    (1) the head height and
    (2) how many gallons per hour (GPH) needed to perform the task.
    Using these two figures, refer to the flow chart for the interested pump.
    Select the model that delivers the necessary flow (GPH) at that specific head height and that meets application standards.
  2. Once this has been completed, adjustments to the pump size may be needed to compensate for the flow restrictions. These restrictions include: elbows or sharp turns in your plumbing, in-line canister filters, and smaller-than-recommended outlet tubing.

Understanding Pump Terminology.

There are many things to consider when choosing a pump but understanding the following information will help to simplify this process.

Submersible Pump:

A Submersible pump operates in water.

In-line or External Pump:

An In-line or External pump only operates out of water. This style is also referred to as a centrifugal pump.

Multi-purpose Pump:

A multi-purpose pump can be used both externally and as a submersible

Head Height:

The vertical distance from the pump to the highest point the water will be pumped to.

Head Pressure:

The water movement is reduced the farther and higher the pump has to push water. Head pressure is created by gravity and will decrease the pump’s output. Pumps are typically rated for the amount of water they can pump without resistance. (Refer to each individual pump series flow charts for detailed information)


This chart illustrates how GPH decreases as head height increases.

• Head Height is the vertical height the pump raises water above the surface of the pond.

• All pumps have a maximum head height.

Friction Loss:

Friction negatively impacts pump performance as water travels through the plumbing. Avoid too many curves or sharp angles in tubing, as well as, elbows and complicated plumbing. Incorrect sizing of pipe or tubing is a common problem and will create unnecessary friction, resulting in reduced water flow. (See graphic)


This image illustrates the impact of tubing size on pump performance. Each container collected the discharge from a 700 GPH pump for 10 seconds with tubing size being the only difference. The conclusion is that too small of tubing restricts the flow dramatically.

Choose the Proper Pipe Size:

(GPH) Gallons per hour is how you determine proper pipe size, not the diameter of the pumps discharge. Many people undersize their plumbing at the expense of the pump performance. Proper pipe size is determined by the maximum GPH capacity of the pump.

Tubing Size Flow Rate:
Max. Water Flow (GPH)Inside Diameter Of TubingUse this chart as a guide in selecting the suggested tubing for each pump size. It shows the maximum flow rate for each size of tubing.
Below Or Above The Water Level:

Pumps in external applications should be located at or below the water level, which is called “Flooded Suction”. Gravity forces the water to the pump and therefore creates a prime. In applications where the pump is located above water level, a “self priming” pump is necessary.


GPH = U.S. Gallons Per Hour

LPM = U.S. Liters Per Minute

FPT = Female Pipe Thread

MPT = Male Pipe Thread

FNPT = Female National Pipe Thread

MNPT = Male National Pipe Thread

Slip = Glue type connection

Barb= Clamp type connection