TerminoxISM Water Filter Sizing

These TerminoxISM water filter sizing instructions are for people with conventional well water systems featuring a well pump and pressure tank. Which is by far the most common well water setup for residences and businesses with private wells.

How to determine your FLOW RATE

The flow rate is the single most important step in determining the correct size of Terminox Filter. Once you know the size filter needed, you can then check that against the water test results to be sure it has the capacity to clean that particular water. And remember that each Terminox is custom made for that particular well. Because we feel that every well is unique.

To determine your flow rate please follow these simple steps.

Open the NEAREST faucet or tap AFTER the pressure tank (But NOT the one ON the pressure tank). And let the water run until the well pump turns on. Immediately turn off the tap and count how many seconds the well pump runs from the time it came on until it shuts off. Then write down the number of seconds the pump ran.

Now get a container you can measure water in, such as an empty gallon milk container. Open the tap or faucet and fill the container. Then close the tap and dump the water down the drain. Fill the container again, and then pour it out again. Continue doing this and counting each gallon until the pump starts again.

Once the pump starts, shut off the tap and stop drawing water. Write down the number of gallons you counted until the pump started. If there are any partial gallons left over count those as well. Such as a total of 1.5 gallons, or 4.25 gallons. You now have the information to calculate the well pump flow rate.

Filter Size

We will then be able to tell you exactly what the flow rate is and which size filter you need. This information is essential to properly size any backwashing filter (such as iron filters and water softeners) or other flow rate dependent items such as Ultra Violet (UV) systems. You should always know your flow rate on ANY private well.

For example: The well pump ran for 30 seconds. And then you were able to draw 5.5 gallons before the pumps started again. That means you have 11 GPM flow rate.

Things to remember when doing a flow rate check:

*DO NOT use a household water hose when checking flow rates. If necessary have someone listen for the pump to turn on while you draw water.

*If you can’t hear the pump turn on and off, follow these instructions.

When you have a pressure tank. Some where near it there will be a small box with some wires connected into it. This is called the pressure switch. Right when the well pump comes on it will make a distinctive “Click”. When the well pump goes off it will make another distinctive click. In this case you may need two people. One to draw water and the other to listen for the clicks.

*Variable Speed Well Pumps and Constant Pressure Well Pumps:

Most residential wells have conventional pumps and pressure tanks. Every now and then we will talk to someone who has a different type. These people usually know who they are because of the special nature of these pumps. If you have a variable speed pump or a constant pressure pump, please call in and ask for a level #4 tech to help you.

Important

Once you have determined your flow rate, you will need to do the following two things.