Clean, healthy drinking water is essential. If you’re in the UK and relying on municipal tap water, chances are you’re already looking for a solution to improve water quality. An under sink water filter offers a powerful and space-saving way to enjoy purified, great-tasting drinking water directly from your kitchen sink.
This guide walks you through everything you need to know about under-sink water filters, including top products, filtration technologies, and answers to common questions.
What Is an Under Sink Water Filter and How Does It Work?
An under sink water filter is a compact system installed beneath your kitchen sink to remove contaminants from tap water. It connects to your water supply and typically dispenses filtered water through a secondary faucet or directly via your existing one, depending on the system.
These filters use different methods such as:
- Carbon filtration to remove chlorine, taste, and odour
- Reverse osmosis for deeper purification including lead, heavy metals, and total dissolved solids (TDS)
- Ultrafiltration membranes for retaining beneficial minerals
The process ensures the removal of harmful substances without affecting water pressure or flow rate.
Under the Sink Filtration vs Over-the-Counter Filters: Which One’s Better?
Compared to countertop or jug filters, under-sink water filters offer:
- Better filter capacity (higher gallons per day)
- Longer filter lifespan (3 to 12 months)
- Consistent flow rate
- No clutter on your kitchen counter
- Higher performance in removing heavy metals and contaminants
If you’re serious about water purification, under-sink water filtration is the top pick.
Top 5 Under Sink Water Filtration Systems in the UK [Tried & Tested]
- Waterdrop G3P800 Reverse Osmosis System
- Flow Rate: 800 GPD
- Filter Lifespan: Up to 12 months
- TDS Reduction: Excellent
- Certifications: NSF Standard 58 & 372
- Pros: Compact, fast flow, filter replacement indicator
- Aquasana AQ-5200
- Filter Capacity: 500 gallons
- Filter Type: Carbon Block
- Taste: Removes chlorine, improves water taste
- Cons: Requires separate faucet
- Frizzlife Under-Sink Water Filter System
- Installation: Direct connect to cold water line
- Replacement: Twist-in filters every 6 months
- Cost: Budget-friendly
- iSpring RCC7AK RO System
- Stages: 6-stage filtration including remineralisation
- Taste: Balanced pH, retains beneficial minerals
- Capacity: 75 GPD
- Brita Total360 Under Sink System
- Design: Sleek under cabinet setup
- Flow Rate: Good for small homes
- Warranty: 1 year
Choosing the Right Water Purifier for Your Kitchen Sink
When selecting an under sink filter, consider:
- Contaminants: Lead, chlorine, chromium-6, TDS
- Filter Capacity: How many gallons it can purify before replacement
- Flow Rate: Measured in GPM, affects water pressure
- Installation: Direct connect vs secondary faucet
- Space: Under cabinet dimensions in inches
- Certifications: NSF, WQA, WRAS
Save Money with an Under Counter Water Filtration System – Here’s How
Using bottled water daily is expensive. An under counter filtration system offers:
- Lower cost per litre
- Longer filter lifespan
- Less plastic waste
- Better performance
With time, the investment pays off with each gallon of clean water you drink.
Why Under Sink Water Purification Systems Are Safer for Your Family
Municipal tap water may contain heavy metals, chlorine, and bacteria. Under-sink filters remove these contaminants, ensuring:
- Clean water for drinking and cooking
- Safer water for children and the elderly
- Protection from harmful chemicals
Systems like reverse osmosis units and carbon filters boost water quality significantly.
Water Purifier for Sink: Who Should Consider It?
Under-sink water filters are perfect for:
- Homes with limited counter space
- Families who value high water quality
- Renters (some models are portable)
- Anyone using dishwasher and wants cleaner water
Installing an Under Cabinet Water Filter – Step-by-Step for Beginners
Most filters come with DIY instructions. Steps include:
- Shut off water supply
- Connect the filter to cold water line
- Mount the unit under sink
- Install separate faucet if needed
- Flush the system
No plumber needed for most units like Frizzlife or Waterdrop.
Under Counter Filter vs Whole House Systems: Which One’s Right for You?
Under Counter Filters:
- Lower cost
- Point-of-use solution
- Great for drinking water
Whole House Systems:
- Higher cost
- Treats all water (bathroom, laundry)
- Not ideal for targeted filtration needs
Final Verdict: Which Kitchen Sink Water Filter System Should You Buy?
If you want the best overall performance, go for the Waterdrop G3P800. For a budget pick, Frizzlife is reliable. If mineral retention is important, iSpring RCC7AK is the right choice.
Look for:
- Filter capacity
- Flow rate
- Installation method
- Certifications
- Warranty
FAQs – Answering Real User Questions
How long do under sink water filters last?
Most filters last 6–12 months depending on usage and water quality.
Is a reverse osmosis system better than carbon filters?
RO removes more contaminants, but carbon filters retain beneficial minerals and are more affordable.
Does under sink filtration affect water pressure?
Only slightly. Models like Waterdrop G3P800 are designed for high flow rate.
Are under sink filters worth the cost?
Yes, they improve water taste, health, and save money on bottled water.
Can I install an under-sink water filter myself?
Most units are DIY-friendly and come with installation guides.
Final Thoughts
A good under sink water filter enhances your home’s water quality, improves taste, and protects your health. Whether you want a simple carbon filter or a reverse osmosis system, there’s a solution that fits your budget and space.
Browse our top picks and choose the right water filtration system for your kitchen today at London Water Filter.