Knowing how to read your pool filter pressure gauge and what to do if it’s not reading right can save you time and money. Most pools come with a pool filter pressure gauge; it’s the gadget that reads the amount of pressure building up inside the filter. Understanding this device is pivotal in keeping your pool healthy and safe.
You should get into the habit of checking your pressure gauge once a week. The typical swimming pool gauge is located on the top of the filter. It's a round device with numbers ranging from 0-60 divided into 10's or 5's by tick marks. The numbers represent the force of water flowing through your system in pounds per square inch or psi for short. Make sure you know what the normal operating pressure is (it should be recorded when a new pressure gauge is installed). Generally, your filter needs cleaning if the pressure rises more than 10 psi over the original marking. Double check in your owner’s manual if this guideline is right for your pool.
If the pressure reads too low, it’s likely that something is blocking the water intake into the filter. The pump uses water to build pressure in the filter, so if something is keeping the water from coming in, the gauge will show the pressure as too low.
If the pressure reads higher than normal, then your filter is working too hard. Your water may be dirty or the filter might need to be cleaned. If cleaning the filter doesn’t help, there may be something wrong with one of the valves in the machine.
If the pressure fluctuates, your water level is probably too low. If your water level is right on the edge, it will fill the skimmer weir—the mechanism that adjusts to changes in water level to take in the right amount—and pressure will gradually build. Then, when the skimmer is sucked dry, the pressure drops again. If your water level isn’t too low, there may be something blocking the skimmer.