Filtration is the very first step in the pool water-treatment process — and one of the most critical. Without effective filtration, even the best sanitation or chemical-dosing systems cannot deliver safe, clear, or compliant water.
Across Australia, a variety of filtration technologies are used in commercial swimming pools, each with its own strengths and limitations. Choosing the right system is essential to protecting swimmer health, reducing operational costs, and ensuring your plant room performs as intended.
Regulations in Australia
As with all parts of the pool water-treatment process, filtration requirements vary from State to State. They may also differ based on facility type, water volume, or expected bather load.
Before making any upgrades or specifying a new filtration system, always confirm compliance with your State or Territory’s Health Department guidelines. A system that meets code from the start helps avoid costly rework and ensures ongoing operational confidence.
Types of Filtration Systems
1. Media (Sand) Filtration
Media filtration — often still referred to as sand filtration — has been successfully used for more than 100 years in both swimming pools and drinking water treatment.
It operates via depth filtration, where debris becomes trapped in the tiny spaces between sand or glass media grains. Water enters from the top and exits clean from the bottom.
Key points:
- Removes particles down to 20 microns.
- Backwashed by reversing the water flow to flush out trapped sediment.
- Media can last 10+ years when properly maintained.
- Reliable and widely used, but limited in removing very fine particles, protozoa, or microscopic pathogens.
2. Cartridge Filtration
Less common in large commercial pools but ideal for spas and small water bodies, cartridge filters offer finer filtration than traditional media systems, sometimes down to 10 microns.
Key points:
- Manual cleaning is required — removing the element and hosing it down.
- In busy commercial environments, elements may need replacing as often as twice per year.
3. Ultrafine Filtration (e.g., B-Ultra)
Ultrafine filters represent a major leap forward in filtration capability. They operate on the same depth filtration principle as media filters but with extremely fine filter media, often with a depth measured in millimetres rather than centimetres.
Perlite-based ultrafine filters, such as the B-Ultra, can capture particles as small as 1 micron — dramatically increasing the removal of microscopic contaminants.
Key points:
- Uses slender perforated tubes to support a fine perlite coating.
- Water flows from bottom to top.
- Captures pathogens and particles far too small for traditional media filters.
- Requires only a small quantity of media, which is dumped during each cleaning cycle.
- Longer runtime between cleans and significantly reduced water waste.
Why Microns Matter
Most harmful pool pathogens are invisible to the human eye — meaning water can look sparkling clean while still posing a risk.
- Chlorine handles most microorganisms well.
- Cryptosporidium is the exception.
- Crypto oocysts measure 4–6 microns.
- They are highly chlorine-resistant, even under superchlorination.
They spread quickly through bather load and are difficult to control without secondary sanitation and ultrafine filtration.
Ultrafine filtration provides a physical barrier capable of capturing these tiny oocysts, preventing them from being returned to the pool and dramatically improving the system’s overall risk-mitigation capability.
Media vs Ultrafine: A Practical Comparison
For a 300,000-litre commercial pool with a required 2-hour turnover rate:
System Footprint
- Media system:
~3 × 1.4 m diameter filters. - Ultrafine system:
~1 × <1.1 m diameter filter. - Outcome:
Reduced equipment footprint → smaller plant room → lower construction and ongoing operational costs.
Backwash Water Use
- Media filters:
~15,000 L per backwash, typically every 2 weeks. - Ultrafine filter:
~4,000 L per clean, with 3–4× longer intervals between cleaning. - Outcome:
Significant water savings + potential reduction in balance tank size.
Is Ultrafine Filtration Right for Your Facility?
Ultrafine filtration offers major advantages for high-bather-load venues, older systems requiring upgrades, and operators seeking lower water waste, finer particle removal, or improved pathogen management.
Whether you’re planning a new commercial build or reviewing an existing plant room configuration, ultrafine filtration is well worth evaluating.
Talk to the Team at Brauer Swim
To discuss filtration options — including whether a B-Ultra Ultrafine Filtration is the right fit for your pool — reach out to the Brauer Swim team.
