Point of Use Water Systems: 6 Popular Options
Point of use (POU) water treatment systems have come a long way. Designed initially for water utilities, advanced treatment technologies were first scaled down to function as whole-house systems then eventually as POU devices. Today, size has decreased, performance has increased and technology choices have expanded, providing homeowners with more options.
If you’re in the market for compact units to filter, purify or soften water, you’ll want to understand what the six most popular POU solutions can and cannot do.
Filtration
Activated Carbon. These filtration units feature activated carbon materials that remove organic and inorganic compounds such as chemical contaminants, chlorine, heavy metals, herbicides and pesticides. They’re effective, require no electricity and don’t waste water, but most units won’t remove asbestos, bacteria, parasites, lead, radionuclides, fluoride, nitrates and sodium.
Ceramic. Made of ceramic material, these filters often incorporate pores one micron or smaller. The small pores capture asbestos, bacteria, cysts and similar particulates, but they don’t remove dissolved compounds such as lead, mercury or trihalomethanes, the byproducts formed from disinfection chemicals like chlorine.
Fiber. Made of spun rayon, cellulose or similar fibers, they’re designed with extremely small pores that sieve particulates from the water flow, so the smaller the pores and the lower the micron rating, the more sediment they can remove. While they effectively capture sand, grit, organic particulates and similar matter, they’re generally not certified for bacteria or parasites and don’t remove dissolved compounds such as lead or mercury.
Purification
Distillers. These units raise water to boiling temperatures, which causes contaminants and dissolved solids to separate so they can be flushed away. They kill bacteria, cysts, parasites and viruses, and remove dissolved minerals (calcium, magnesium) heavy metals, nitrates, radionuclides and salt. They’re affordable but require electricity, so there are ongoing operational costs.
Reverse Osmosis (RO). One of the most popular under-sink solutions, RO devices feature a fine membrane that screens biological contaminants such as bacteria, cysts, parasites and viruses, as well as chloride, chromium, copper, lead and salt. They don’t require electricity, but some units use significant volumes of water for processing and membrane cleaning, which wastes water and adds to costs.
Softening
Ion Exchange. These devices remove dissolved minerals to improve water quality. Cation exchangers soften water by removing calcium, iron and magnesium and are most common, while anion exchangers remove chloride and sulfate. Both typically use water to recharge (clean) the unit, flushing used water down the drain which adds to costs and requires more water.
Regardless of technology, many units incorporate or can be paired with supplemental filters to remove more contaminants and enhance water quality, so consult your plumber to select a configuration that suits your needs. If you have the latitude, invest in high quality devices with the versatility and capacity to adapt as your household needs evolve.