A micron is a unit of length, equal to one twenty five thousandth of an inch (1 / 25,000), and is used often when describing the size of particulates a swimming pool filter system can capture.
What does Micron mean for swimming pools?
Micron is a standard unit of length. One micron is equivalent to 1/25,000 of a single inch, and is typically used to describe the size of small particles like contaminates flowing through a medium like air or water. As an example, a single human hair is roughly 30 to 120 microns in diameter. Bacteria, microbes, mold spores, and other organic contaminates found in water are usually measured in microns, as they are much smaller than can be seen with the unaided eye.
Although sanitizing a pool with chlorine or bromine helps to oxidize contaminates, particles remain in the pool that are not destroyed by sanitation chemicals or shocking the pool and must filtered out to keep pool water clear and sparkling. For each type of pool filter, there is a varying amount of microns which may be captured. Sand filters capture particles down to about 20-40 microns. A cartridge filter may debris and contaminates down to about 10-15 microns. DE filters can be trap contaminates down to 2-5 microns. Up flow filters can capture particulate smaller than one micron.