If you’re tired of paying for bottled water, an under-sink water filter can save you money and improve the taste of your tap water. These compact systems usually fit in tight spaces under sinks.
Most use reverse osmosis, which uses pressure to push water through a semipermeable membrane. They reduce contaminants including sediment, chlorine odors, fluoride, herbicides and pesticides. Many models also include displays that let you know when your filters need replacing.
1. Reverse Osmosis
Reverse osmosis is one of the best ways to filter water. It removes contaminants and sediments down to a molecular level, leaving only clean water behind. It also reduces nitrates and other contaminants in well water.
You can see the reverse osmosis process at work in this easy experiment: put freshwater and a concentrated solution of salt on opposite sides of a semipermeable membrane, and then apply pressure to the concentrated side. The molecules will naturally migrate to the freshwater side, as they are less concentrated.
Quality reverse osmosis systems use a multistage approach to treat the water. They produce the highest quality water with lower energy consumption than other systems. They can even remove chemicals, such as lead and chlorine, from water.
Many under-sink reverse osmosis systems come with a tank so the filtered water is available right away. However, you can also get a tankless configuration that treats the water as it flows through the system. This can be a great option if you want to eliminate the wait for the high-quality water you deserve.
2. Pre-Filter
A pre-filter is an important addition to any water filtration system. It works to eliminate dirt, sand, silt, rust and other large suspended particles from the water before it goes through your primary filter. This protects the primary filter from damage and clogging, which extends its life.
There are several different types of pre-filters available on the market. They can be made from mesh, nylon fiber or a honeycomb material. They all have a similar function and all work to remove large debris from the water. Most are washable and affordable to replace.
Some pre-filters are transparent and allow you to see the sediment that it collects on the bottom of the unit. Others are not and require you to use a vacuum or spray out the collected contaminants from the base of the filter. One of our favourites is the Waterco MultiCyclone pre-filter because it doesn’t have any moving parts and has a clear collection base that makes cleaning easy.
3. Carbon Block Filter
Carbon block filters are a great choice for removing organic chemicals, VOCs (volatile organic compounds), pesticides, herbicides, chlorine and its by-products, as well as heavy metals like lead. They are also an excellent taste-and-odor filter. They are easy to maintain and bind pollutants permanently, so they will not wash away from aqueous solutions.
Carbon blocks are made from finely ground activated carbon combined with a binding agent that holds the granules together to form a dense, solid block. This allows them to perform much better than granular activated carbon (GAC) filters because the uniform pore structure increases water contact time and enhances performance via adsorption.
Multipure uses two manufacturing processes to create high-quality carbon block cartridges – extrusion and compression molding. Both involve heating the materials to activate the carbon and then forcing them into a rigid, dense block using heat and pressure. This design enhances the chemistry of the carbon to produce more effective chemisorption, physisorption and catalysis filtration than GAC. It also produces a filter with more consistent flow rate. End caps on both ends of the carbon cylinder help ensure that the carbon is forced through, and an outer wrap helps minimize carbon fines while offering aesthetic design options.
4. Activated Carbon Filter
Activated carbon filters eliminate or reduce a wide range of unpleasant odors and tastes in water. These water purifiers also reduce toxins and organic chemicals. They are very effective at reducing the concentration of chemicals like lead, mercury, chlorine and chloramines. They also remove traces of drugs, pesticides and herbicides in drinking water.
They work by a process called adsorption, whereby contaminants are attracted to and held by the surface of the carbon material as water passes through. Large organic molecules with more weight have a stronger tendency to associate with the carbon surface than they do with dissolved water molecules. The carbon’s pore channels have different sizes, with the largest pores picking up bigger molecules while the smaller, finer pores pick up more soluble impurities.
Activated carbon water filters can be used for whole house or refrigerator filtration as well as countertop models such as the Springwell RP-2000 and Aquasana Rhino. They can also be used with ion exchange and ultrafiltration layers to reduce minerals in the water such as calcium (limescale). This type of filter can be effective at removing PFAS/PFOS which are synthetic chemicals used in a variety of products including fire-fighting foam, metal plating and stain repellents. These chemicals have been shown to be bioaccumulative and toxic to mammal species.
5. Micron Filter
A filter with a micron rating of 1 or less is perfect for removing sediments, chemicals and metals from your water. This size is also ideal for reducing bacteria and cysts. While filters with a higher micron rating are more effective at reducing contaminants, they also tend to have a shorter lifespan and can be susceptible to extreme clogging.
Sediments such as dirt, sand and rust are common in most tap water supplies. These can clog pipes, cause damage to appliances and produce bad tasting water. Filters with a micron rating of 1 or lower are able to remove all types of sediment from your water. These filters can also help reduce dissolved minerals and organic chemicals. They are also often designed to reduce cysts such as giardia and cryptosporidium.
A 1-micron filter will not only trap sediments but will also reduce many viruses and bacteria. This is the ideal choice for many families and businesses that want to ensure that their drinking water is safe and clean. These types of filters are also great for removing cysts such as giardia or cryptosporidium, and for reducing chlorine taste & odor.