Why 3 Stages?
A single-stage filter catches one category of contaminant. A 3-stage system works in sequence — each canister targeting a different size or type of particle — so nothing gets through. This is the same approach used in commercial food-service filtration, and it's what we recommend for households that want thorough whole-house treatment rather than just a rough sediment block.
Doncaster is supplied by Yarra Valley Water from the Eastern Water Treatment Plant. While Melbourne's water is generally high quality, Doncaster properties in older streets can experience sediment from pipe corrosion, and residents commonly report chlorine taste in the summer when dosing increases. A 3-stage system addresses both.
What Each Stage Does
Catches sand, silt, rust, and pipe debris. Protects the downstream filters from premature loading.
Removes chlorine, chloramines, taste, odour, and a range of organic compounds and VOCs.
Final polishing stage — catches any remaining fine particles and chemical traces that passed stage 2.
About This Installation
The photo shows the completed system installed in the garage — a practical location that keeps the unit accessible for filter changes while protecting it from the weather. Three 20-inch Big Blue canisters sit in a Waterman stainless steel frame marked "IN" on the left and "OUT" on the right. Copper pipe feeds in from the top, with the mains supply running left-to-right through the filter stages before distributing to the rest of the house.
The redundant vacuum system unit visible to the left of the filter frame is unrelated to the filtration system — it was already in the garage. The filtration unit is entirely self-contained in its stainless frame.
Standard domestic filter canisters are 10 inches tall and hold around 1 litre of filter media. Big Blue canisters are 20 inches tall and hold significantly more — they have a higher flow rate (suitable for whole-house use without pressure drop) and filter cartridges last 2–3 times longer before needing replacement. For a household using water at multiple points simultaneously, Big Blue is the right size.
Pressure Drop — Is It a Problem?
This is the most common question about whole-house filtration. The short answer: with correctly sized Big Blue canisters and fresh filter cartridges, pressure drop through the system is minimal — typically 10–20kPa at normal household flow rates, which is imperceptible at the tap. Pressure drop increases as cartridges load up with sediment, which is a useful indicator that it's time for a filter change.
If your property already has low mains pressure (below 350kPa), we'll discuss options before installation — including whether a pressure reducing valve is needed or whether the system is suitable for your property.
Filter Replacement in Doncaster
For a 3-person household, cartridge replacement is typically needed every 9–12 months for the sediment stage and every 12 months for the carbon stages. We can replace them for you as part of a service call, or supply the cartridges so you can do it yourself — the canisters unscrew by hand with the included filter wrench, and the isolation valves on the frame mean you don't need to shut off the whole house to do it.
3-Stage Filtration in Doncaster — Fixed Price
We supply the system, handle the plumbing, and install it properly. Call for a fixed-price quote on a whole-house filter system for your Doncaster home.