Old Building Pipes and Rooftop Tanks in Hong Kong: Do You Need a Home Water Filter?
Plenty of Hong Kong residential buildings are decades old. Residents of older buildings sometimes wonder about the state of the internal pipes or the rooftop tank, and whether a home water filter is worth installing. This article is not out to manufacture worry — it walks Hong Kong residents through how home water actually arrives, the steps a household can take to find out more, and how to choose a home filter, if one is wanted, around the household's real needs.
How Hong Kong homes get their water: from street main to tap
Understanding the supply path helps residents see who manages each link.
Drinking water in a Hong Kong home generally travels this route:
WSD street main → building basement tank or booster pump system → the building's internal pipes → rooftop tank (in some buildings) → the taps on each floor and in each flat
The Water Supplies Department is responsible up to the building's inlet. Once inside, the internal pipes, pump rooms and rooftop tanks are generally managed day to day by the property management company or the owners' corporation. Maintenance arrangements and supply methods vary from building to building.
About rooftop tanks
Not every Hong Kong home depends on a rooftop tank. Some newer or refurbished buildings use pressurised direct supply, with no rooftop storage. If unsure how your building is supplied, ask the management office.
Steps a resident can take first
A resident with questions can first learn about the building's supply through these channels, then decide whether anything further is needed:
1. Ask the management office
- The rooftop tank's regular cleaning and inspection schedule
- Maintenance records for the building's internal pipes (if any)
- Any recent supply-related repairs or notices
2. Check the WSD's public information
The Water Supplies Department's website carries information on drinking water safety, supply arrangements and water testing, useful as reference.
3. Consider professional water testing
With a specific concern, consider commissioning a licensed laboratory to test the water, and decide the next step from real data. Results vary by building and by time — a single test only reflects that sample at that moment.
Supply conditions differ building by building — never judge on age or hearsay alone.
Common misconceptions about older buildings and filters
Misconception 1: an old building must have water problems
Building age is only one reference point. The building's upkeep, pipe renewal record, tank cleaning frequency, and whether it has switched to pressurised direct supply all shape the actual picture. Do not judge on age alone.
Misconception 2: a filter solves everything
A home filter is one option in a household's daily drinking arrangements, but it cannot substitute for building-level supply management, pipe maintenance or repairs. If the building's supply system needs repair, raise it with the management office through the proper channels and follow up.
Misconception 3: every home needs the same filter
Kitchens, daily usage, habits and living situations (owner or tenant) all differ. Choose a filter around the household's actual circumstances, not a one-size-fits-all rule.
When to consider a home water filter
Residents in the following situations might consider a filter as part of their daily drinking arrangements:
- A personal preference about the taste or smell of the tap water, and a wish for an extra filtration step
- Higher daily drinking volumes at home, and a wish for more convenient supply
- Having asked the management office, wanting one extra arrangement for the household's drinking water
- Having tested the water, wanting to weigh a suitable option against the results
Choose a filter from the household's real needs and habits — not from fear.
RO838 vs DT400: the home comparison
Below is a comparison of Bio-Link's two home options in residential settings. Bio-Link can advise on the right option and assess the installation against your kitchen space, inlet and drain positions, existing equipment and household habits.
| Home situation | General direction | Reference option | Installation requirements |
|---|---|---|---|
| Owner, with ample under-sink space | Consider an under-sink reverse osmosis system | RO838 | British three-pin socket, water inlet, drain point; Bio-Link handles installation |
| Tenant, or under-sink installation unworkable | Consider a countertop model for flexibility | DT400 / DT400F | British three-pin socket and water inlet; no drain point needed; Bio-Link handles installation |
| Limited kitchen space | Assess whether a countertop unit fits | DT400 / DT400F | The DT400 / DT400F are countertop dispensers, suited to homes with limited kitchen space or where under-sink installation is awkward; still allow room for the unit, its connections and daily use. |
| Existing filtration in place, wanting to work with current equipment | The DT400 can work with an existing filter | DT400 | The DT400 can connect to a suitable filtered water outlet by site conditions; Bio-Link will suggest the right connection against the existing filter, inlet position and kitchen layout. |
| Renovating, with kitchen changes planned | Plan the under-sink installation conditions into the renovation | RO838 | Bio-Link can assess and advise on an RO838 installation against the kitchen space and inlet position. |
About the RO838
RO838 is Bio-Link's home under-sink reverse osmosis (RO) filter, installed beneath the kitchen sink, filtering certain substances from the water through an RO membrane, with the filtered water drawn from its own tap.
Installation requirements
- British three-pin power socket
- Under-sink water inlet
- Drain point (RO systems need drainage)
- Installation by Bio-Link
Maintenance arrangements
- Cartridges and membrane generally replaced every 6 to 12 months, depending on usage
- A more frequent schedule can be requested as needed
Maintenance period
- RO838 main-unit maintenance is arranged annually
Notes for tenants The RO838 needs under-sink installation and a drain connection, which does not suit every tenancy. Tenants should obtain the landlord's consent before installing; Bio-Link can assess feasibility on site and advise. Where under-sink installation is unworkable, the DT400 / DT400F is the more flexible alternative.
About the DT400 / DT400F
DT400 / DT400F is Bio-Link's home countertop dispenser. Users can choose the built-in filtration version (DT400F) or pair it with the home's existing water filter.
Installation requirements
- British three-pin power socket
- Water inlet
- No drain point needed (not an RO system)
- Installation by Bio-Link
Suited situations
- Tenants, or homes where under-sink installation is unworkable
- Limited kitchen space that rules out an under-sink system
- Existing filtration in place, to be used together
- Households wanting hot and cold options
Maintenance arrangements
- Cartridges generally replaced every 6 to 12 months, depending on usage
Questions to weigh before choosing a home filter
Before contacting a supplier, work through these questions to pin down the right option:
- Is there enough under-sink space in the kitchen?
- Owner or tenant?
- Roughly how much drinking water does the household use daily?
- A brand-new filtration installation, or working with existing equipment?
- How do budget and future cartridge costs weigh in?
Explore Bio-Link home filtration options
If you are considering a filter for your home, work through the questions above, then contact Bio-Link about the right option and an installation assessment.
- RO838: an under-sink RO system with annual main-unit maintenance, for owners and households with under-sink conditions
- DT400 / DT400F: with optional built-in filtration, for tenants and homes short on kitchen space
The above is for reference; the final plan follows Bio-Link's latest product information and an on-site assessment. A filter can form part of daily drinking arrangements, but cannot substitute for the building's supply management, pipe maintenance or professional water testing.
Frequently asked questions
Must residents of older buildings install a filter?
Not necessarily. Supply conditions differ building by building — never judge on age alone. Ask the management office about the rooftop tank's cleaning and upkeep first; with a specific concern, consider professional water testing, then decide from the actual picture.
How do the RO838 and DT400 differ?
The RO838 is an under-sink reverse osmosis (RO) filter, needing under-sink space, a water inlet and a drain point. The DT400 / DT400F is a countertop dispenser, with optional built-in filtration or pairing with an existing filter, needing no drain point — suited to tenants and tight kitchens. See the Bio-Link product pages for full specifications; Bio-Link can also advise specifically against your kitchen space, existing equipment and habits.
Can tenants install a water filter?
It depends on the landlord's permission and the building's rules. Under-sink installations (such as the RO838) involve water and drain connections — obtain the landlord's consent first. The DT400 / DT400F is countertop and far more flexible; Bio-Link can suggest the right option, and how to handle it at move-out, against the existing equipment, kitchen layout and habits.
What does installing a water filter require?
All models need a British three-pin socket and a water inlet. The RO838 also needs a drain point. Bio-Link handles installation and can assess feasibility on site and advise.
How often does the filter cartridge need to be replaced?
Under ordinary use, every 6 to 12 months. The actual frequency depends on usage and the model, and a more frequent schedule can be requested. Bio-Link will suggest the right schedule by model, cartridge configuration and household usage.
Does installing a filter mean water quality is no longer a concern?
A filter can form part of the household's daily drinking arrangements, but cannot substitute for the building's supply management, pipe maintenance or repairs. If the building's supply system needs repair, raise it with the management office through the appropriate channels.