AquaForte UltraSieve III – 3 × 110 mm Inlets – Max Flow 6,000 GPH
Market-Leading Stainless Steel Sieve Pre-Filter for Large ponds & Swimming Ponds
The AquaForte UltraSieve III (3 × 110 mm inlets) is the high-capacity version of the industry’s most trusted mechanical pre-filter.
Designed for large koi ponds and swimming ponds, it delivers exceptional waste removal, silent operation, and long-term reliability using a proven, low-complexity design with only one moving part.
This is the reference standard for gravity-fed pre-filtration.
 
Why UltraSieve III Is the Benchmark
Most efficient pre-filter for (swimming) ponds
Extremely reliable – single moving part
True waste separation – debris removed before breakdown
Stainless steel sieve element – never needs replacing
Silent operation – no vibration, no noise
No water loss – closed-loop system
Waste is 100% recyclable
Very easy to maintain
Market leader for 15+ years
If water quality matters, this is the correct mechanical stage.
 
How It Works (Proven Sieve Technology)
Pond water enters via three 110 mm gravity inlets
Water flows over a moving weir connected to a float
The float automatically regulates water level to match pump demand
Water passes over a curved stainless steel sieve
The sieve consists of hundreds of triangular stainless steel rods:
Spaced 200 or 300 microns (0.2–0.3 mm)
Set at a 7° angle
Solid waste remains on the sieve
Clean water falls through to the main filter
Crucially, debris is removed before it can be chopped up by the pump, preventing dissolved pollution and improving biological filtration efficiency.
 
Maintenance (Fast, Simple, Predictable)
Not self-cleaning by design
Open the large slide valve
Flush debris away in seconds
No brushes, foams, or consumables to replace
Low effort. Low running cost. High reliability.
 
Key Technical Details
Maximum flow: up to 6,000 GPH
Inlets: 3 × 110 mm gravity inlets
Sieve element: Stainless steel (200 or 300 micron options)
Rod angle: 7° for optimal separation
Debris outlet: Large outlet with slide valve
Housing: Heavy-duty polypropylene
Pump protection: Long suction pipe draws water from beneath the float to prevent air draw
Engineered for continuous, high-flow operation.
 
Ideal Applications
Large koi ponds
Swimming ponds
High-stock systems
Gravity-fed filter rooms
Professional and commercial installations
 
Bottom Line
The AquaForte UltraSieve III (3 × 110 mm, 6,000 GPH) is the definitive mechanical pre-filter for serious pond systems. Proven, silent, consumable-free, and exceptionally reliable, it removes waste properly—before it becomes pollution.
If you are building or upgrading a high-performance koi or swimming pond, this is the correct starting point.