Can you fall ill from using water from a dirty water tank?

Yes. A dirty water tank breeds bacteria such as E. coli, Salmonella and Legionella. The common effects are diarrhoea, food poisoning, skin infections and breathing problems. Children and the elderly are the most easily affected.

How often should a water tank be cleaned to avoid these dangers?

The Ministry of Health Malaysia recommends at least once a year. For homes with babies, elderly family members or chronic patients, TangkiBersih recommends every 6 months.

Is boiling water enough to kill bacteria from the tank?

Boiling kills bacteria but does not remove heavy metals, rust or sediment. It also does nothing for the water you bathe in. Water tank cleaning removes the source of the problem, not just its effects.

How do I check my water tank without climbing onto the roof?

Look at the tap water after a supply disruption. If it is cloudy, yellowish or carries fine sand, the tank needs cleaning. Send photos of the tap and the tank by WhatsApp and our technician can assess them from the pictures.

7 Dangers of Dirty Water Tanks Most People Don't Know

Why a Dirty Water Tank Is Dangerous for Your Family

The water from your tap comes from the water tank on your roof. If that tank is dirty, the water is dirty. Many families use this water to cook, bathe and brush their teeth every day.

Most water tanks in Malaysia have never been cleaned since they were installed. After two to three years, the tank floor carries a layer of sludge, rust and algae. Here are the 7 dangers that come with a dirty water tank.

1. E. coli and Salmonella Bacteria

A damp, dark and warm water tank is a breeding ground for bacteria. E. coli and Salmonella get in through a lid that does not seal properly. Insects, rats and bird droppings are the usual sources.

The effects are diarrhoea, vomiting and food poisoning. Children and the elderly are the worst affected.

2. Legionella Bacteria

Legionella multiplies in stagnant water between 25 and 45 degrees Celsius. Rooftop water tanks in Malaysia sit in this temperature range almost every day.

The bacteria spread through fine droplets when you shower. They can cause a serious lung infection.

Clear water from a water tank that has just been cleaned and sanitised

3. Moss and Algae in the Water Tank

A tank without a lid, or a translucent tank, lets light in. Green algae grow on the inner walls within a few weeks.

Algae change the colour and smell of the water. They also become food for other bacteria. A water tank with algae almost always has a bacteria problem as well.

4. Sediment and Heavy Metals

Every supply disruption carries mud into the tank. Old pipes add flakes of rust. After a few years, this layer can be several centimetres thick.

This sediment can contain lead, iron and manganese. Heavy metals build up in the body little by little. The effects are not visible straight away.

5. Skin Infections and Itching

Contaminated water causes itching, rashes and worsening eczema. Children who bathe in dirty tank water often have skin problems that never clear up.

Many families change their soap and shampoo again and again. The real cause is inside the water tank.

6. Damage to Household Appliances

Sediment and rust flow into water heaters, washing machines and water filters. Scale builds up inside the heater. Filters clog faster than they should.

Replacing a water heater costs far more than water tank cleaning from RM150.

7. Changes in Water Smell and Taste

A fishy smell, a metallic taste or yellowish water is the clearest sign. Many people get used to the smell over time. Visitors notice it straight away.

For homestays and guesthouses, this directly affects customer reviews.

Who Is Most at Risk?

Babies and children: their immune systems are not yet mature.
The elderly: more prone to dehydration from diarrhoea.
Pregnant women: an infection can affect the pregnancy.
Chronic patients: diabetes, kidney disease and chemotherapy patients.

If anyone in your household falls into these groups, clean the water tank every 6 months.

Is Boiling Water Enough?

Boiling kills bacteria. It does not remove heavy metals, rust or sediment. Those stay in the water and end up in your cooking.

Boiling also does nothing for the water you bathe in. Skin and shower-related problems continue until the tank itself is cleaned. Water tank cleaning removes the source, not just the symptoms.

How Often Should a Water Tank Be Cleaned?

The Ministry of Health Malaysia recommends water tank cleaning at least once a year. That is the minimum for a sealed poly tank in a normal housing area.

For homes with babies, elderly family members or chronic patients, every 6 months is safer. The same applies to homestays and guesthouses, where guests drink and bathe in the water. A full sanitisation with a written report is available from RM200 for these premises.

A schedule of every 6 to 12 months keeps the sediment thin. The clean is faster, the cost is lower and the water stays safe in between.

How to Tell if Your Water Tank Is Dirty

Simple signs you can spot without opening the tank:

Tap water is cloudy after the supply is restored.
Fine sand at the bottom of a cup or in the sink.
Yellow stains on taps and the bathtub.
A fishy smell in the morning.
More than a year since the last clean.

The full list is at signs your water tank needs cleaning.

What You Can Do Today

Check the tank lid. Make sure it seals and is not cracked.
Do not drink straight from the tap without boiling or filtering first.
Schedule water tank cleaning every 6 to 12 months.
Keep a record of the last cleaning date.

The Right Water Tank Cleaning Process

Rinsing with water alone is not enough. Proper water tank cleaning has 6 steps: pump out, scrub, high-pressure rinse, sanitise, inspect and refill. Read our professional water tank cleaning process for the details of each step.

TangkiBersih uses food-grade sanitising agents. They are safe for drinking, cooking and bathing water. Every job comes with a 30-day warranty.

Do not wait until your family falls ill. WhatsApp TangkiBersih for a quote within 15 minutes. We clean water tanks across Malaysia.