A tap water filter filters mains water the moment you draw it, with no jug to fill and no tank to wait for. There are two types: countertop models, which connect to your existing tap with no plumbing work, and under-sink models, hidden in the cabinet and connected to their own tap. Nice Water brings together the tap filters from Pure Filters and Coldstream: here is how to choose between them.
The 4 tap filters compared
| Model | Installation | Work needed | Cartridge | Cartridge capacity |
|---|---|---|---|---|
| Pure Filters Flow Tap | On the countertop, connected to the kitchen tap | None, suitable for tenants | CTO MAX CF1075W | 3,000 litres or 6 months |
| Pure Filters Classic Tap | Under the sink, with the 2-way mixer tap included | Qualified plumber | MAX CF1082W | About 5,000 litres or 6 months |
| Coldstream CA566 | Under the sink, with an outlet tap fitted on the worktop | Connection to the cold water supply | CTO MAX CF1075W | 3,000 litres or 6 months |
| Coldstream CA653 | Under the sink, connected to a separate tap | Qualified installer | MAX CF1082W | About 5,000 litres or 6 months |
Countertop or under-sink: how to choose
- You rent, or you do not want any work done: choose the Flow Tap, which sits on the countertop. It attaches to your existing tap; a diverter valve lets you switch between mains water and filtered water.
- You want a clear worktop and a single tap: the Classic Tap replaces your mixer with a 2-way model. Filtered water has its own lever, and the filter stays hidden under the sink.
- You want a stainless steel under-sink filter with a small dedicated tap: the CA566 sits in the cabinet and feeds an outlet tap fitted next to your mixer.
- You filter a lot of water: the Classic Tap and the CA653 use the CF1082W cartridge, designed for about 5,000 litres between changes, against 3,000 for the other models.
What the Coldstream cartridges filter
Both cartridges combine a ceramic with activated carbon. According to the Coldstream technical data sheet for the CTO MAX CF1075W, measured between 4,000 and 6,000 litres, beyond its 3,000-litre capacity:
- lead and pesticides, including glyphosate, reduced by more than 99.9%;
- nitrates reduced by 95.6% at 4,000 litres, then by 88.5% at 6,000 litres;
- arsenic reduced by 78 to 94% depending on the volume.
PFAS were not measured on the CF1075W. On the CF1082W, according to its technical data sheet, they were measured between 6,000 and 10,000 litres, beyond its capacity of about 5,000 litres: PFOA reduced by 91 to 99.9% and PFOS by 97 to 99%.
These figures come from laboratory tests under standard conditions: actual results may vary with your water. The results for each cartridge are on its product page.
What a tap filter does not do
These filters connect to cold water only, and to mains water or water that has already been disinfected. They are not water softeners: they do not remove limescale. Without running water, in a chalet, when camping or during a supply cut, a gravity water filter takes over.
Frequently asked questions
Do I need a plumber to fit a tap filter?
Not for the Flow Tap, which sits on the countertop: it connects to the existing tap with the adapter supplied. Yes for under-sink models, the Classic Tap, CA566 and CA653, which connect to the cold water supply.
When should the cartridge be changed?
About every 6 months, or sooner if the filtered volume is reached: 3,000 litres for the Flow Tap and the CA566, about 5,000 litres for the Classic Tap and the CA653.
Does filtered water keep its minerals?
According to Coldstream, ceramic and carbon filtration retains mineral salts such as calcium and magnesium, which preserves the taste of the water.
