Why Does My Tank Water Taste, Smell or Look Different?

Safe drinking water should be clear, tasteless, and odourless. If you’ve noticed your tank water looks different, smells unusual, or has developed an odd taste, it’s absolutely worth paying attention to.

Not only can these changes be unpleasant, they are often a sign that something has changed within your water supply and should be investigated.

The good news is that your water often gives you clues about what is happening inside your tank. By recognising these signs early, you can identify potential issues before they become bigger problems.

If you have any concerns about your water quality, our expert team is only a phone call away and is always happy to help point you in the right direction.

Why Does My Tank Water Smell?

Unusual odours are often the first sign that something has changed in your water supply. Three of the most common smells we come across are:

Earthy or Musty

Usually caused by leaves, sediment, or other organic matter breaking down inside the tank and getting into solution in your water. Heavy rain can stir this buildup into the water, making the smell more noticeable. It is typically a sign that your water tank should be cleaned.

Rotten Egg

Often associated with hydrogen sulphide gas or sulphur-reducing bacteria. This should be investigated promptly. Adding an antibacterial treatment can help reduce bacteria in your water tank until a full clean can be completed.

Strong Foul Odour

May indicate a bird, rodent, or other animal has entered the tank through a damaged lid or opening and requires immediate attention.

If your water suddenly develops an unusual smell, it should never be ignored. Taking a look inside the tank can help identify what factors may contribute to the change in smell.

Why Has My Tank Water Changed Colour?

Brown Water

This is one of the most common signs that sediment has built up and/or been disturbed inside the tank.

Heavy rainfall, recent storms, very low water levels, or too long without cleaning can mean material from the bottom of the tank goes into suspension in your water supply.

It may also indicate that sediment levels have accumulated to the point where they are approaching the tank outlet, increasing the likelihood of sediment being drawn into your water supply.

Green or Yellow Water

Green water is often a sign of algae growth in your tank, usually caused by sunlight entering the tank through loose lids or gaps.

In rainwater-fed systems, a yellow or tea-like colour can also be caused by tannins and natural pigments from leaves and other plant matter washing into the water.

The discolouration may be caused by organic material and sediment breaking down within the tank, or by foliage and debris trapped in gutters decomposing and washing coloured water into the tank during rainfall.

Both are signs that your tank and collection system should be inspected and cleaned.

We recommend inspecting and cleaning the gutters to remove any accumulated foliage and debris.

Cleaning the tank to remove the organic material and sediment already present will also help improve water quality and reduce the likelihood of further discolouration.

Orange or Red Water

If your water has an orange, rusty, or reddish tint, high iron levels may be the cause.

This is commonly seen in bore or spring-fed water supplies, where naturally occurring iron dissolves into the groundwater before entering your tank.

While a tank clean can remove any settled iron sediment, the source water will continue to introduce more unless it is properly treated.

In these cases, a suitable pre-treatment or water filtration system is the best long-term solution.

Murky or Cloudy Water

Murky or cloudy water can be a sign of chemical contamination, such as residue from roof washing products reacting in the water.

It may also indicate elevated bacterial activity within the tank. If your water suddenly becomes cloudy or milky-looking, it is best to stop and investigate the cause before continuing to drink it.

Important: If your water is reaching your taps with noticeable colour or cloudiness, it is a sign your sediment filters may be overloaded. Suspended particles, elements such as iron and pigments can shield bacteria from UV light, reducing the effectiveness of your UV system and impacting the safety of your drinking water.

Why Does My Tank Water Taste Different?

A change in taste is often the most detectable sign that something has affected your water supply.

The most common tastes we hear about are:

Earthy, Musty or Swampy

Caused by sediment buildup or decaying organic matter inside the tank. This is especially common after heavy rainfall stirs up material that has settled on the bottom.

Metallic or Chemical

Often linked to contamination from roof cleaning or house washing chemicals, which can linger on surfaces longer than expected before washing into the tank.

In some cases, a metallic flavour may also be caused by ageing plumbing or naturally occurring minerals in the source water such as bores.

Fishy

Often associated with elevated bacterial activity within the tank or algae growth. Organic matter, stagnant water, or contamination entering the system can encourage bacterial growth, leading to an unpleasant fishy smell or taste. This is a sign that the tank and water supply should be inspected promptly.

If your water suddenly develops an unusual taste, particularly a chemical one, it is best to investigate the source before continuing to use it for drinking.

What Should You Do Now?

Although changes in smell, taste, and colour can appear very different, they are often caused by the same underlying issues. Sediment buildup, blocked gutters, overhanging trees, damaged lids, wildlife access to your water tanks, or poor maintenance can all contribute to declining water quality.

If you notice a sudden change in your water, it should not be ignored. Store-bought antibacterial treatments can help reduce bacterial levels, and if your tank is full, using water until it reaches around half capacity allows incoming rainfall to dilute the existing supply.

However, these are only short-term measures. The sediment and organic material at the bottom of the tank often act as the source of ongoing contamination, which is why a professional water tank clean is usually the safest and most effective solution.

Removing this buildup while identifying the cause of the problem is the best way to restore and protect your water quality long term.

Thereafter, regular annual tank cleans help maintain your water quality and allow your filtration and other protective measures to work as effectively as possible.

Keep Your Water Safe

Your tank water should always be clear, fresh, and pleasant to drink. If the taste, smell, or colour changes, your water is often telling you that something needs attention.

If you’ve noticed something unusual in your water supply, the Safe H2O team is here to help.

In most cases, our professional tank cleaning process can restore your water quality without the need to dump thousands of litres of stored water.

By removing natural contaminants, sediment, and bacteria from your existing supply, we help ensure your water is clean and safe to drink while also identifying the source of the issue to minimise the risk of it happening again.

Whether you need expert advice, a tank clean, or guidance on improving your filtration system, get in touch today and let us help keep your water clean and safe.