Choosing a drinking water filter for your home – 5 things to check first (Indonesia)
Anyone in Indonesia who wants to make tap water (PAM) or well water safe to drink is spoilt for choice: from inexpensive sediment filters to reverse osmosis (RO) systems. These different types of filters can perform very differently. In this article, we explain the differences and the five points you should check before buying.
Summary
- Sediment, activated carbon, UV and RO filters tackle different problems. Only reverse osmosis also removes dissolved substances such as limescale, salts, heavy metals and nitrate.
- Check the following before buying: water source, water pressure, consumption, space under the sink and running costs.
- The TLW 2 and TLW 4 operate without electricity and require 3–6 bar water pressure. The TLW 7 has its own pump and operates from as little as 1 bar.
1. What can each type of filter do?
| Filter type | Removes | Does not remove |
|---|---|---|
| Sediment filter | Sand, rust, suspended solids | dissolved substances, chlorine, germs |
| Activated carbon (e.g. carbon block) | Chlorine, odour, taste, many organic substances | Limescale, salts, nitrate, TDS |
| UV lamp | neutralises bacteria and viruses | Particles, chemicals, dissolved substances |
| Reverse osmosis (RO) | removes the majority of dissolved substances (lime, salts, heavy metals such as lead, iron and manganese, nitrate), particles, bacteria and viruses | – is combined with pre- and post-filters |
In our RO systems, an activated carbon block acts as the first stage (Core+ OS) to protect the membrane from particles and chlorine. After the membrane, the Core M OS post-filter provides additional hygienic protection.
2. Five points you should check before buying
Water source
Does your water come from the mains (PAM) or from your own well (sumur)? For mains water, the system can be connected directly. Well water often contains iron, manganese, limescale or nitrate. In such cases, depending on the water quality, pre-treatment such as a sediment or iron/manganese filter is required upstream of the system. A water analysis will show what your water needs.
Water pressure
The TLW 2 and TLW 4 operate without a pump and require 3–6 bar. Measure the pressure before buying, for example using a simple pressure gauge attached to the tap. Many houses in Indonesia are supplied via a water tank on the roof (toren). Without a pump, such a tank only delivers around 0.1 bar per metre of head, so in the kitchen the pressure is usually well below 3 bar. The solution is a pressure pump installed upstream of the system. It can be located on the water tank or in the utility room. The TLW 7, with its compressor pump, generates around 10 bar itself and requires only a minimum of 1 bar at the inlet.
Consumption
How much water do you need per day – just for drinking, or for cooking as well?
- TLW 2: around 0.5 litres per minute straight from the membrane.
- TLW 4: around 80–90 litres per day at 4 bar, stored in a 4-, 6- or 8-litre stainless steel tank. When you run the tap, the water flows at full flow straight away; the tank refills in around 15–40 minutes.
- TLW 7: approximately 2 litres per minute straight from the tap, without a tank. Suitable for large families and, in villas, for the whole house.
Space, electricity and tap
The units are connected to the cold-water supply under the sink (TLW 2 and TLW 4: 470 × 480 × 115 mm). The TLW 7 requires a power socket; the TLW 2 and TLW 4 do not. For the filtered water, we recommend a 3-way stainless steel tap or a separate tap. Small parts made of copper or brass may leach substances into the water.
Running costs and waste water
Take into account not only the purchase price but also the cost of filter replacements: Core+ OS every 6 months (Rp1,200,000), Core M OS every 12 months (Rp2,200,000), and the membrane every few years. Furthermore, every RO system produces waste water (concentrate). With the TLW 2, this amounts to around 2 litres per litre of purified water; with the TLW 4, it is 2 to 3.5 litres, depending on the mains water pressure. Thanks to its own control system, the TLW 7 manages with around 1 litre. You can collect the concentrate for watering plants or cleaning.
3. Which TLW system is right for whom?
| TLW 2 | TLW 4 | TLW 7 |
|---|---|---|
| Electricity required | no | No |
| Principle | Direct, without a tank | Stainless steel tank 4/6/8 L |
| Output | ±0.5 L/min | ±80–90 L/day |
| Water pressure | 3–6 bar | 3–6 bar |
| Pure water : Waste water | 1 : 2 | 1 : 2 to 1 : 3.5 |
| Mineralisation | not possible | possible |
| Price (including first filter) | Rp28,400,000 | Rp33,400,000 + tank |
Conclusion
First, decide which problem you want to solve (taste and chlorine, bacteria or dissolved substances), then check the water pressure, electricity supply, consumption and space available. Not sure? Send us a photo of your water connection and your pump’s pressure gauge via WhatsApp – we’ll tell you which system is right for you.