[instructions] How to connect water filtration under the sink

Why, which, with what and how to install a water filtration system also under your sink? Find out everything you need to know about choosing and installing a cartridge water filtration system here and now.

Why you also want a water filter

Fabulous "living water" can be bottled from your tap. Okay, it won't have the miracles of the fairy tale. But definitely this water will taste absolutely luxurious. Such crystal clear drinking water will flow into your tap after passing through filtration.

Special filters prevent the passage of unwanted water components. These are organic substances, foreign particles (e.g. rust or sand particles). They also remove unpleasant water odours caused by chlorine.

A good filter can also work with water mineralization, whereby thewater is enriched with magnesium - among other things, it supports coffee extraction -at the expense of the calcium content in the water, which is responsible for the well-known and unpleasant problem of limescale. If you use filtered water, it will greatly extend the life of your coffee machine or water kettle.

See, I didn't even go overboard with the live water to begin with. Let's summarize the benefits of a water filter in a neat list.

What are the benefits of a water filter

  • Protection from dirt, coarse and fine foreign particles in the water
  • elimination of chlorine, etc. organic substances reducing the quality of drinking water
  • reduction of carbonate hardness of water, leading to scale problems
  • mineralization of water with magnesium ions (Mg²⁺) to improve water properties

PS: If you go ahead with the installation of a water filtration system from BWT, you can also add the advantage of easy installation and future cartridge replacement.

What to start with - choosing a water filtration system

The absolute most convenient solution for water filtration is to install a water filtration system with replaceable cartridges. Because you're tired of constantly making filtered water little by little from a filter kettle. If you have a coffee maker with a direct water connection, then ...wait you don't have cartridge filtration yet?

Don't worry, we'll get this missing device for perfect water out of your tap right away. It will be a two-level decision:

  1. Filter cartridge type - classic BWT Bestmax, premium BWT Bestmax or BWT Bestprotect
  2. cartridge capacity - sizes S, V, M, XL, 2XL

Differences in BWT cartridges - water filters

BWT bestmax BWT bestmax PREMIUM BWT bestprotect
5-stage filtration 5-stage filtration 5-stage filtration
activated carbon filter activated carbon filter activated carbon filter
decarbonisation filter decarbonisation filter decarbonisation filter
filtration of water and bypass water and bypass filtration water and bypass filtration
easy installation and maintenance easy installation and maintenance easy installation and maintenance
vertical and horizontal connection Vertical and horizontal connection Vertical connection only
in sizes X, S, V, M, L, XL, 2XL in sizes S, V, M, XL, 2XL in sizes S, V, XL
magnesium mineralisation pH stabilisation
protection against CaSO4-2H2O

Tables of settings and filtration capacities of BWT cartridges

The required cartridge size is calculated from the estimated required capacity. Thus how many litres of water will flow through the cartridge until the next replacement (the cartridge lifetime is always a maximum of 1 year after connection). The filtration capacity decreases in proportion to the increase in the overall water hardness.

How to determine the correct water filtration capacity

We want 10 l of filtered water per day from a BWT bestmax PREMIUM cartridge. This means that approximately 3650 litres per year will flow through the filter. We can consider (according to the table below) a size V, but we still need to find out the total hardness of our water. According to the "drip" water test, we will find a value of, say, 14°TH. And now we are sure that the ideal for us will be BWT bestmax PREMIUM XL with the bypass setting (by pass) at number 3.

BWT bestmax

Size X S V M L XL 2XL
(A) Height without bracket in mm 280 360 420 475 500 500 574
(B) Height incl. bracket in mm 300 385 445 500 530 530 600
(C) Connection height in mm 230 310 370 425 450 450 520
(D) Filter body in mm 88 88 115 130 145 145 185
Weight in kg, (dry / in operation) 0.5/1.1 0.9/1.5 2.1/3.2 2.4/4.2 3.4/5.9 3.8/6.0 7.5/11.0

Beverage dispensers without steam generation
Total water hardness Bypass Size
X S V M L XL 2XL
<7°dTH 3 >1025 >1710 >4285 >6510 >8910 >11655 >20570
8°dTH 3 900 1500 3750 5700 7800 10200 18000
10°dTH 3 720 1200 3000 4560 6240 8160 14400
12°dTH 3 600 1000 2500 3800 5200 6800 12000
14°dTH 3 510 855 2140 3255 4455 5825 10285
17°dTH 3 420 705 1765 2680 3670 4800 8470
20°dTH 3 360 600 1500 2280 3120 4080 7200
23°dTH 3 310 520 1300 1980 2710 3545 6260
25°dTH 2 <255 <430 <1075 <1635 <2235 <2925 <5160

Hot beverage preparation with steam generation
Total water hardness Bypass Size
X S V M L XL 2XL
<7°TH 3 >855 >1425 >3570 >5425 >7425 >9710 >17140
8°TH 3 750 1250 3125 4750 6500 8500 15000
10°TH 3 600 1000 2500 3800 5200 6800 12000
12°TH 2 445 745 1865 2835 3885 5080 8965
14°TH 2 380 640 1600 2430 3330 4355 7685
17°TH 1 265 445 1115 1695 2320 3030 5355
20°TH 1 225 375 945 1440 1970 2575 4550
23°TH 1 195 330 825 1250 1715 2240 3955
25°TH 1 <180 <300 <755 <1150 <1575 <2060 <3640

BWT bestmax PREMIUM

Size S V M XL 2XL
(A) Height without bracket in mm 360 420 475 500 574
(B) Height incl. bracket in mm 385 445 500 530 600
(C) Connection height in mm 310 370 425 450 520
(D) Filter body in mm 88 115 130 145 185
Weight in kg, (dry / in operation) 0.9/1.5 2.3/3.2 2.8/4.2 4.0/6.0 7.8/11.0

Beverage dispensers without steam generation
Total water hardness Bypass Size
S V M XL 2XL
<7°dTH 3 >1285 >3085 >4625 >7370 >12000
8°dTH 3 1125 2700 4050 6450 10500
10°dTH 3 900 2160 3240 5160 8400
12°dTH 3 680 1630 2450 3900 6350
14°dTH 3 580 1400 2100 3340 5440
17°dTH 3 430 1035 1550 2470 4025
20°dTH 3 365 880 1320 2100 3420
23°dTH 3 315 765 1145 1825 2975
25°dTH 2 <290 <700 <1055 <1680 <2735

Hot beverage preparation with steam generation
Total water hardness Bypass Size
S V M XL 2XL
<7°TH 3 >1070 >2570 >3855 >6140 >10000
8°TH 3 935 2250 3375 5375 8750
10°TH 3 750 1800 2700 4300 7000
12°TH 2 565 1360 2040 3250 5290
14°TH 2 485 1165 1750 2785 4535
17°TH 1 355 860 1290 2060 3355
20°TH 1 305 730 1100 1750 2850
23°TH 1 265 635 955 1520 2480
25°TH 1 <240 <585 <880 <1400 <2280

BWT bestprotect

Size S V M XL 2XL
(A) Height without bracket in mm 360 420 475 500 574
(B) Height incl. bracket in mm 385 445 500 530 600
(C) Connection height in mm 310 370 425 450 520
(D) Filter body in mm 88 115 130 145 185
Weight in kg, (dry / in operation) 0.9/1.5 2.1/3.2 2.8/4.2 3.8/6.0 7.5/11.0

Hot beverage preparation with steam generation
Total water hardness Size
S V M XL 2XL
<7°TH >855 >2140 >3143 >5125 >8570
8°TH 750 1875 2750 4458 7500
10°TH 600 1500 2200 3590 6000
12°TH 505 1250 1833 2620 5000
14°TH 440 1070 1570 2245 4285
17°TH 380 880 1294 1850 3525
20°TH 310 750 1100 1570 3000
23°TH 240 600 957 1175 2400
25°TH <225 <556 <880 <1090 <2220

To install water filtration under the sink, prepare

The main thing - the type of cartridge, we have selected. Now let's list the necessary accessories for installing the water filtration under the sink. So, in addition to the cartridge, you will need the following to connect the filtration:

  • Pressure flexi tubing to connect the water from the line to the filtration and from the filtration to the faucet/coffee maker,
  • BWT Besthead Flex connection head for cartridge filtration,
  • I highly recommend you also get the BWT Protector mini as a pre-cartridge particulate filter, especially if you expect to use filtered water for your coffee maker (the plumbing in the coffee maker has very narrow components that even small particles in the water could clog).
  • It's also handy to have a BWT AQA monitor with an LCD to check the water flow through the filter, because that way you'll have accurate data on filter usage, whether you change it too early or too late. After all, a new cartridge isn't exactly a penny item, is it?
  • And then of course additional connecting hoses and fittings (reducers, elbows) as needed, or according to the specific types of threads on the water inlet, faucet, coffee maker water inlet, etc. You have to see what you actually have under the sink. ????

I'll also mention the necessary DIY equipment, i.e. what tools will come in handy when installing a water filtration system: tighteningwrenches and gaskets like silicone tape will also help.

How to install water filtration under the sink

Now we come to the final step, the actual installation of the water filtration system.

  1. Check and prepare your water filter, accessories and tools for installation so that you have everything together and handy.
  2. Get under your sink, or the place of your choice where you want to install the water filtration system.
  3. If you'll be splitting the water supply for the unfiltered water and the water for the filtration,turn the lever on the water shut off to the off position before disconnecting the current hose from the sink faucet . (No kidding. More than one such "plumber" got an ice shower right off the bat.)
  4. Now just assemble the filtration system according to the diagram below. (Note that the diagram shows a general water filtration assembly and does not include wiring for individual accessories.)
  5. Don't forget toset the "by pass" on the filter cartridge head to the correct value you know from the water hardness test and tables earlier in this article.
  6. Done. Turn the water shutoff valve to the "on" position, now you can test your filtered water and check that nothing is leaking or drippinganywhere under the sink.

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