When it comes to purifying your tap water, you have two main options – an undersink water filtration system or a countertop water filter pitcher. Both provide an effective way to remove contaminants from your drinking water and improve the taste. However, each has its own unique pros and cons.
In this blog post, we are going to compare both these filtration systems by discussing their definitions, working mechanisms, and benefits to determine which is the best.
Undersink Filter
Undersink water filters are installed directly under your kitchen sink. The filter housing connects to your home’s main water supply line coming into the kitchen.
How Undersink Filters Work
Undersink filters use one or multiple filtration stages to cleanse water as it passes through. A basic under sink system will contain a sediment filter as the primary stage. This filter traps and removes particles like rust, silt, and sediment to improve clarity.
Many undersink filters also incorporate an activated carbon block filter. This block contains millions of tiny pores coated with activated carbon. As water percolates through the block, contaminants like chlorine, lead, mercury, volatile organic compounds, herbicides, and pesticides are attracted to and adhered to by the carbon particles. This helps to reduce chemicals, odors, and impurities in tap water.
For higher levels of treatment, some undersink filters add a third stage like a mechanical or KDF filter. Mechanical filters have even smaller pores that can take out particles down to 1 micron in size to remove sediment, parasites, and cysts. KDF filters use a proprietary zinc alloy mesh that alters water chemistry and removes heavy metals.
Benefits of Undersink Filters
- Treats water for the whole house at once rather than just a single faucet or pitcher. The entire home receives purified water.
- Lower ongoing costs versus purchasing replacement cartridges for a countertop filter since it’s a one-time installation cost. Cartridges typically last 3-6 months.
- More filtration power and customizable capabilities with multi-stage systems to remove a wider range of contaminants like parasites, cysts, heavy metals and volatile organic compounds beyond just basic sediment.
- Inconspicuous installation out of sight under the sink so it doesn’t take up valuable counter space.
- Filtration occurs right at the source before water reaches fixtures so you don’t have to transfer water or use a separate container for drinking.
Countertop Filter
Countertop water filters are portable pitchers or faucet-mounted units that purify water as it passes through the removable filter cartridge during dispensing. These systems sit directly on your kitchen counter to purify water on demand for drinking and cooking purposes.
How Countertop Filters Work
Countertop water filters utilize either a pitcher-style or faucet-mounted design. In both cases, untreated tap water is poured or flows into the top reservoir section above the built-in carbon block filtration cartridge.
Gravity then causes the water to slowly trickle down through the porous carbon block. Contaminants like chlorine, mercury, lead, VOCs and other chemicals are adsorbed onto the activated carbon particles. The purified water collects in the bottom chamber ready for use.
Some countertop systems feature additional pre-filtration screens or meshes to catch sediment and particles before reaching the carbon block. More advanced multi-stage units may incorporate mechanical or ion exchange capability as well.
Maintenance only requires replacing the cartridge every 2-3 months depending on water quality and usage. The old one is easily swapped out from the top of the unit.
Benefits of Countertop Filters
- Portable and space-saving design that doesn’t require plumbing or permanent installation.
- Quick and easy to use – just fill and dispense cleaner water on demand without infrastructure changes.
- More affordable upfront cost than installing a whole house undersink system.
- Ability to filter water directly at the tap or faucet for cooking and drinking purposes rather than having to transport it from another location.
- Additional cartridge options are available like specialized filters targeting particular contaminants like lead.
- Some models are certified to reduce substances like chlorine that impact water taste beyond basic purification standards.
| Feature | Undersink Water Filter | Countertop Water Filter |
| Installation | Requires permanent installation under the sink; connects to plumbing. | No installation needed; just place on the counter or attach to a faucet. |
| Filtration Scope | Whole house filtration (treats all water that passes through the sink). | Filters water on demand; typically used for drinking and cooking. |
| Filtration Stages | Often multi-stage (e.g., sediment filter, carbon block, KDF, mechanical). | Generally single or dual-stage (carbon block with possible pre-filtration). |
| Contaminants Removed | Wide range of contaminants (chlorine, lead, mercury, VOCs, heavy metals, parasites, etc.). | Primarily chemicals, chlorine, VOCs, and some heavy metals. |
| Cost (Upfront) | Higher initial cost due to installation and system setup. | Lower upfront cost; no installation fees required. |
| Cost (Ongoing) | Replacement cartridges every 3-6 months, are generally cost-effective. | Cartridges are replaced every 2-3 months, generally cheaper but more frequent. |
| Water Flow Rate | Provides a high flow rate as water is filtered directly from the source. | Slower filtration rate as water trickles through the filter (especially pitcher types). |
| Capacity | Can handle a higher water volume (entire household usage). | Limited to the capacity of the pitcher or unit; for small-scale use. |
| Maintenance | Requires periodic cartridge replacement; easy to access under the sink. | Cartridges need frequent replacement but are easy to swap. |
| Space Considerations | Hidden under the sink; it doesn’t take up counter space. | Takes up counter space or attaches to the faucet, may clutter your kitchen. |
| Water Taste Improvement | Significantly improves taste by removing more chemicals and impurities. | Improves taste but might not be as thorough in removing contaminants as multi-stage under sink filters. |
| Ease of Use | Once installed, no manual filling is required; water is filtered directly from the tap. | Requires manual filling (in the case of a pitcher) or faucet attachment. |
| Aesthetic Impact | Hidden from view; it does not impact the kitchen’s aesthetics. | Visible on the countertop; may affect kitchen aesthetics. |
| Best For | Homeowners looking for long-term, robust filtration solutions. | Renters, small households, or those seeking a quick, affordable option for clean water. |
So…Which is better?
From our perspective, both undersink and countertop filters are good. If you have small water usage requirements, then a countertop system is the way to go. Whereas, if you have a large family and want decent filtered water, then undersink may be better. But, the final decision totally depends on your personal preferences.
