Water filtration questions answered

Yes. All reticulated tap water in Australia must meet the Australian Drinking Water Guidelines (ADWG), which set health limits for hundreds of contaminants including bacteria, heavy metals, pesticides and disinfection by-products. Water authorities test constantly and publish annual quality reports.

That said, "safe" and "great tasting" are not the same thing. Water can be perfectly safe but still taste of chlorine, leave scale on your appliances, or carry dissolved minerals that affect cooking. Filtration is about quality of life as much as health.

TDS (Total Dissolved Solids) measures the total concentration of dissolved minerals, salts and metals in water — expressed in mg/L (milligrams per litre). It's a broad measure of mineral content, not a direct health indicator.

• Under 200 mg/L — Excellent. Clean, fresh tasting.
• 200–400 mg/L — Good. Most Perth desalination-blend areas.
• 400–600 mg/L — Moderate. Noticeable in taste. Groundwater-heavy zones.
• Above 600 mg/L — Elevated. More common in regional areas.

High TDS doesn't mean the water is unsafe — it just means there's more mineral content. If taste matters to you, an under-sink reverse osmosis unit can reduce TDS to under 50 mg/L for drinking and cooking water.

Hardness measures dissolved calcium and magnesium in water, expressed in mg/L as calcium carbonate. It's the main cause of limescale — the white crusty build-up on taps, shower heads and inside appliances.

• Under 60 mg/L — Soft. Minimal scale risk.
• 60–120 mg/L — Moderate. Some scale over time.
• 120–180 mg/L — Hard. Scale treatment recommended.
• Above 180 mg/L — Very Hard. Significant scale damage to appliances without treatment.

Hard water is not a health risk — calcium and magnesium are beneficial minerals. But it significantly shortens the life of hot water systems, dishwashers and washing machines, and makes cleaning harder. Perth has some of the hardest water in Australia, particularly in groundwater-supplied northern suburbs.

Perth water is chloraminated — treated with chloramine (a combination of chlorine and ammonia) rather than free chlorine alone. Chloramine is a more stable disinfectant that maintains residual protection through the pipe network to your tap.

It's safe, but some people are sensitive to the taste and smell, particularly in cold water or after the water has been sitting in pipes. A quality activated carbon block filter reduces chloramine effectively and is the single most impactful upgrade you can make to drinking water taste.

Perth water has fluoride added at 0.6–0.9 mg/L, within the ADWG guideline of 1.5 mg/L. This level is considered safe and is added for dental health benefit.

Most whole-home filters do not remove fluoride, including activated carbon blocks. If you specifically want to reduce fluoride for drinking water, you need one of:

• Reverse osmosis (RO) — removes 94–98% of fluoride at the tap
• Activated alumina — a dedicated fluoride reduction media

If fluoride removal is not a concern, standard carbon filtration is fine. The fluoride level in Perth water is well within health guidelines.

NSF/ANSI certification standards tell you what a filter has been independently tested to remove:

• NSF 42 — Aesthetic effects only: chlorine, taste, odour, sediment. Does not cover health contaminants.
• NSF 53 — Health effects: lead, heavy metals, volatile organic compounds (VOCs), cysts (Cryptosporidium, Giardia), and other health contaminants. A meaningful upgrade over NSF 42.
• NSF 58 — Reverse osmosis systems. Covers TDS reduction as well as health contaminants.

When choosing a filter, NSF 42 is the bare minimum. We recommend NSF 53 at Stage 3 as a worthwhile health protection upgrade for most Perth homes, regardless of water zone. Ask suppliers for their certification documentation — some claim compliance without independent verification.

WaterMark is Australia's mandatory plumbing product certification scheme, administered by Standards Australia. It certifies that a product is safe for connection to the water supply and won't contaminate it — covering materials, pressure ratings and installation compatibility.

Under Australian plumbing codes, any product connected to the water supply must carry WaterMark certification. If a supplier installs an uncertified product and your hot water system or pipes fail, your insurance may not cover the claim.

This is one of the key things we check in our supplier reviews. AquaCo (WaterMark #23448) is one of the strongest performers on this criterion. Some suppliers claim certification without a verifiable licence number — always ask for it.

A whole-home filter (also called point-of-entry or POE) is installed on the main water supply line before it branches to the rest of the house. Every tap, shower, appliance and garden tap receives filtered water.

You'd choose whole-home filtering if you want to:

• Protect appliances from scale and sediment (dishwasher, washing machine, hot water system)
• Improve water quality for showering and bathing — chloramine absorbs through skin
• Reduce scale on shower heads, tiles and tapware across the house

If you only care about drinking water quality, an under-sink or bench-top filter at the kitchen tap is a more affordable starting point.

Most quality whole-home systems use three filter stages in sequence, each targeting different contaminants:

• Stage 1 — Sediment (5 micron): Removes particles, sand, rust flakes and fine debris. Protects downstream stages and extends their life.
• Stage 2 — Activated carbon block: Removes chlorine, chloramines, taste and odour compounds, and some organic chemicals. NSF 42 rated minimum.
• Stage 3 — Zone-specific: Varies by your water. TAC scale minimiser for hard water, iron reduction media for iron-heavy zones, or NSF 53 carbon for heavy metals and VOC protection.

Our water quality lookup tells you which Stage 3 is most relevant for your Perth suburb.

Reverse osmosis forces water through a semi-permeable membrane with pores so fine (0.0001 micron) that it removes virtually everything — dissolved salts, heavy metals, fluoride, nitrates, bacteria, viruses and TDS — producing near-pure water.

It's the most thorough filtration method available for home use. The trade-offs:

• Produces waste water (typically 3–4 litres rejected for every 1 litre of filtered water)
• Removes beneficial minerals along with contaminants — a remineralisation post-filter is recommended
• Slow flow rate — suited to an under-sink drinking water tap, not whole-home
• Higher cost and more maintenance than a standard carbon system

For most Perth households, RO makes most sense as an under-sink drinking water unit alongside a whole-home carbon/TAC system — not as a whole-home solution.

Under-sink filters connect to the mains supply beneath the kitchen sink and typically feed a dedicated filtered water tap mounted on the benchtop. They're hidden, have higher flow rates, and can handle multi-stage systems including RO. Require a plumber for installation.

Bench-top or counter-top filters sit on the bench and connect to the existing tap via a diverter valve — no plumbing required. They're portable, cheaper, and easy to install yourself. Flow rate and filtration capacity are lower, and they take up bench space.

For a rental property or a first filter, a bench-top is a practical starting point. For a permanent home, under-sink is the better long-term investment.

Yes, but bore water requires more specialised treatment than scheme water. It commonly contains elevated iron, manganese, hardness, hydrogen sulphide (rotten egg smell), and sometimes bacteria — the specific issues depend heavily on your bore's depth and location.

You need a water test first. Without knowing what's in your bore, it's impossible to specify the right media. A good bore water system typically includes:

• Aeration or oxidation to deal with iron and manganese
• Sediment filtration
• Catalytic carbon or dedicated iron/manganese media
• UV disinfection if bacteria is present

From our reviewed suppliers, Integraflow and Water2Water both handle bore water systems and can arrange testing. Don't let any supplier quote you a bore water system without seeing a water test result first.

TAC (Template Assisted Crystallisation) is a scale prevention method that uses polymer beads to convert dissolved calcium and magnesium into microscopic crystals. These crystals stay suspended in the water rather than attaching to surfaces — so they pass harmlessly through your pipes and appliances without forming hard scale.

Key facts about TAC:

• Does not soften water — hardness minerals remain in the water, just in a different form
• No salt, no electricity, no waste water — unlike traditional salt-based water softeners
• Media typically lasts 3–5 years before replacement
• No ongoing running costs beyond media replacement
• Works best when water passes through at the right flow rate — oversizing or undersizing the unit reduces effectiveness

It depends on what you're trying to achieve:

• Salt-based water softener: Removes calcium and magnesium entirely via ion exchange, replacing them with sodium. Produces genuinely soft water with zero scaling. Requires salt top-ups (typically 10–25kg per month for a family), regeneration cycles using water, and a drainage connection. Water is not recommended for drinking due to elevated sodium.
• TAC scale minimiser: Prevents scale without removing hardness minerals. No salt, no waste water, no sodium in your drinking water. Less effective if you need very low hardness for a specific purpose.

For most Australian households, TAC is the practical choice — it solves the real problem (scale damage to appliances) without the ongoing cost and complexity of salt management. Salt softeners are more common in commercial laundry and industrial applications where true soft water is necessary.

At hardness above 180 mg/L — which affects areas like Yanchep, Two Rocks, Butler and Neerabup — you'll notice:

• White chalky deposits on shower screens, tiles and tapware within weeks
• Shower head flow reducing noticeably within 6–12 months from scale build-up inside
• Dishwasher performance declining and internal components scaling up
• Hot water system element scale build-up significantly reducing efficiency and lifespan
• Soap lathering poorly — hard water requires more detergent and shampoo to produce the same result

Water Corporation's own data flags these areas with a note: "Elevated hardness is characteristic of the source supplying this locality." Scale treatment is not optional at these levels if you want appliances to last.

Dishwasher salt protects the dishwasher's internal ion exchange resin — it helps the dishwasher itself, but does nothing for your hot water system, washing machine, shower screens, taps or pipes. It's a separate system entirely.

If you're in a hard water zone, you need scale protection at the water inlet (whole-home TAC) to protect all appliances and fixtures. Using dishwasher salt alongside a whole-home TAC system is still a good idea — they're complementary, not alternatives.

Yes, for a whole-home system. A whole-home filter connects to the main water supply line — this is licensed plumbing work under Australian law. In WA, all work on water supply connections must be carried out by a licensed plumber.

Under-bench and bench-top single-tap filters can sometimes be installed by a competent DIYer using a standard compression fitting (check your specific product), but a whole-home system is not a DIY job if you want it insured and compliant.

Costs vary significantly by system type and supplier. Rough ranges for a Perth installation:

• 2-stage carbon + sediment: $600–$900 installed
• 3-stage with TAC scale minimiser: $900–$1,500 installed
• 3-stage + under-sink RO drinking water: $1,400–$2,200 installed
• Bore water systems: $1,800–$4,000+ depending on what the water test reveals

Annual running costs (cartridge replacement) are typically $80–$180 per year for a standard 3-stage system, depending on water quality and usage. See our full cost breakdown guide for detailed year-by-year analysis.

Yes — several suppliers offer rental agreements. Water2Water is the main Perth-based supplier offering rental, typically from around $30–$50/month including maintenance.

Rental can make sense if you:

• Don't want upfront capital cost
• Are renting your property and want the landlord to take over the asset
• Want maintenance included without managing cartridge schedules

Over 5+ years, ownership is almost always cheaper than rental — but rental removes the hassle. Check the contract terms carefully: minimum terms, exit fees and what happens if you move.

A properly installed, WaterMark-certified whole-home filter is considered a fixture and adds to the property. Buyers increasingly look for them, particularly in hard water suburbs. A scale minimiser protecting appliances is a genuine selling point.

The caveat: an uncertified or poorly installed system can work against you — a building inspection may flag it as a defect. Use a licensed plumber and a WaterMark-certified product.

Technically yes, but it depends on whether it's classed as a fixture. A whole-home system installed in a fixed housing with plumbing connections is typically considered a fixture and stays with the property unless you negotiate otherwise before purchase or specify it in a rental agreement.

Under-sink or bench-top filters are easier to take — they're generally not fixed. Confirm with your solicitor if you're buying or selling.

It depends on cartridge type, water quality and household usage:

• Sediment cartridges (Stage 1): Every 6–12 months. In Perth's groundwater-heavy zones with elevated iron, closer to 6 months.
• Carbon block (Stage 2): Every 12 months typically. Chloramine-heavy supply depletes carbon faster.
• TAC scale media: Every 3–5 years. Not a cartridge — a media replacement.
• NSF 53 carbon (Stage 3): Every 12 months.
• RO membrane: Every 2–3 years. Pre-filters every 6–12 months.

Manufacturers' guidelines are usually based on average conditions. If your sediment stage is visibly clogged or water pressure drops noticeably, change it earlier regardless of schedule.

An overdue sediment cartridge restricts flow and pressure, and may rupture, sending captured particles downstream. An exhausted carbon cartridge stops reducing chloramine — your water returns to unfiltered quality and you may not notice immediately because taste changes slowly.

More seriously, an overloaded carbon stage can become a site for bacterial growth if left long enough in warm climates. In Perth's summer heat, this is a real consideration for systems that sit unused during holidays and are then used again without cartridge checking.

Yes — cartridge replacement is not licensed plumbing work. You are replacing consumable media inside an existing housing, not making new water connections. Most housings use a standard sump wrench (often provided) and the process takes 10–15 minutes.

This is one reason we strongly recommend standard-sized housings (20" × 4.5" for whole-home) rather than proprietary supplier formats. Standard cartridges are available from Bunnings, plumbing suppliers and online — often for $15–$40 each. Proprietary cartridges can cost 3–5× more and you're locked into one supplier for life.

Start with the simplest explanations first:

• Chlorine/chemical taste returning: Carbon cartridge is exhausted. Replace it.
• Musty or earthy taste: Possible bacterial growth in an old cartridge or housing. Replace cartridge and sanitise housing.
• Metallic taste: Could be old pipes, or a change in supply water. Check water authority notices.
• Sulphur/egg smell: Usually groundwater-related or a hot water system issue — not a filter problem.
• Taste suddenly changed with no cartridge change: Water authority may have changed source blend or chemical treatment. Check their website or call them.

If in doubt, call your filter supplier — most offer troubleshooting support over the phone.

The most important ones:

• "What is your WaterMark licence number?" — If they can't give you one, walk away.
• "Is the filter cartridge a standard size?" — 20" × 4.5" for whole-home. If proprietary, you're locked in.
• "What NSF certification does your carbon block carry?" — Minimum NSF 42. NSF 53 for health contaminants.
• "Does the quote include installation, commissioning and a water pressure check?"
• "What is the annual filter replacement cost, and where can I source replacements?"
• "Do you offer a service agreement, and what does it cover?"

Our full consultation checklist covers 40+ questions across all aspects of the purchase — print it and bring it to supplier meetings.

The main traps:

• Equipment-only pricing: Always compare fully installed prices. Some suppliers quote equipment and add $300–$500 for installation separately.
• Proprietary cartridges: A cheap system with expensive proprietary cartridges costs more over 5 years than a pricier system with standard cartridges.
• Unverifiable certification claims: Ask for the WaterMark number and verify it at watermark.gov.au. Some suppliers claim WaterMark certification for products that aren't listed.
• Google review count vs rating: 4.9 stars from 12 reviews is less reliable than 4.5 stars from 800 reviews.

Use our side-by-side comparison tool to see all Perth suppliers across 10 criteria — certifications, filter lock-in risk, cost of ownership and more — without a sales pitch.

Not necessarily. Price correlates loosely with filtration quality at the low end — very cheap systems often use poor-quality media or small housings with low flow rates. But above a certain threshold, price is more about brand, margin and proprietary components than actual filtration performance.

A well-specified 3-stage system using standard housings and quality carbon (NSF 53 certified) from a mid-tier supplier will outperform an expensive proprietary system from a supplier with high margins and locked-in cartridges — and cost significantly less over 10 years.

It depends on your priorities and budget:

• Just drinking/cooking water: An under-sink filter at the kitchen tap is the most cost-effective starting point. $300–$600 installed, $40–$80/year in cartridges.
• Scale protection for appliances: You need whole-home. A TAC scale minimiser on the kitchen tap doesn't protect the hot water system, dishwasher or washing machine.
• Chloramine reduction for showering: Whole-home. Chloramine absorbs through skin in the shower — a kitchen filter doesn't help.
• Complete solution: Whole-home carbon + TAC, plus under-sink RO for drinking. Best outcomes, higher cost.

If budget is a constraint, start with a kitchen under-sink filter and add whole-home when finances allow — the systems can coexist.

Yes, with some constraints:

• Bench-top filters: No landlord permission needed. Connect to any tap via a diverter. Portable when you move.
• Under-sink filters: Requires a connection under the sink — technically minor plumbing that may need landlord consent. Many landlords agree since it adds value. Get it in writing.
• Whole-home systems: Requires landlord permission and is considered a fixture. Some rental properties already have them. Consider a rental filter agreement (Water2Water offer this) — the system stays with the property when you leave.

A bench-top gravity filter (no plumbing at all) is a zero-friction option for renters who just want better drinking water quality.