Pond Filters & Filtration Systems

Physically removes solid particles — leaves, algae, fish waste, sediment — before they break down and pollute the water. Pond skimmers handle surface debris; pre-filters and sieves handle suspended solids. Without mechanical filtration, biological media clogs and stops working. This stage needs regular cleaning.

Provides surface area for colonies of beneficial bacteria that convert toxic ammonia (fish waste) → nitrite → nitrate through the nitrogen cycle. BioFalls filters, biological chambers, and K+ media all serve this role. Without biological filtration, ammonia builds to lethal levels in fish ponds. This stage should be cleaned gently and infrequently.

UV light disrupts the cell walls of free-floating algae, causing clumps that mechanical filtration then removes — eliminating green water. UV does not replace mechanical or biological filtration but dramatically improves water clarity in sunny or high-fish-load ponds. Built into many pressure and gravity filters we carry.

Mechanical. Mounted at the water surface edge, captures floating debris before it sinks. Houses the pump. The first stage in any properly built ecosystem pond. Size by pond surface area and pump flow rate.

Biological. Sits at the top of the waterfall — water flows in from the pump, passes through biological filter media, and spills over the weir to create the waterfall. Pairs with a skimmer to form a complete ecosystem pond filtration loop.

Mech + Bio + UV. Compact, can be buried or placed anywhere. Pressurized flow allows flexible placement. Most include built-in UV clarifier. Best for small-to-medium ponds where space is limited or a BioFalls setup isn't practical.

Mech + Bio. Water flows through by gravity after being pumped up. Handles higher flow rates than pressure filters, easier to clean, and generally more effective for medium-to-large ponds. Must be placed above the water return level.

Premium mech + bio + UV. Compact professional-grade units combining all filtration stages in one housing. Self-cleaning or easy-clean designs. For serious koi keepers who want best-in-class results with minimal plumbing complexity.

Pump + mech + bio + UV in one unit. Fully submerged — no external plumbing required. Simplest install possible. Best for small decorative ponds and water gardens where maintenance ease is the priority.

OASE carries the broadest filter lineup on the site — from the Filtral UVC all-in-one submersible at $215 to the BioTec ScreenMatic² automatic self-cleaning filter at $4,615. The BioPress UVC series covers small pressure filtration; the FiltoClear series handles medium-to-large pressure filtration with UV; the BioSmart handles gravity-flow; the BioTec ScreenMatic² is the flagship for large koi ponds that need automatic cleaning. Best for: any pond size, reliable German engineering, clear water guarantee.

Range: $187–$4,615 · All filter types covered

Aquascape invented the ecosystem pond concept and their Signature Series BioFalls and skimmer components are the most widely installed filtration system in North America. BioFalls are sized in 1000/2000/4000-gallon tiers; matching Signature Series skimmers complete the ecosystem loop. If you have an Aquascape pond kit, the Signature Series is the correct matched replacement or upgrade. Best for: ecosystem pond builds, Aquascape system owners, BioFalls waterfall filtration.

Range: $300–$700+ · Skimmers + BioFalls

Evolution Aqua makes some of the most respected koi pond filtration equipment in the world. The EazyPod and EazyPod Complete are compact all-in-one koi filters with exceptional mechanical and biological performance. The Cetus Sieve is the preferred gravity-fed pre-filter for bottom drain koi pond systems. The Tempest handles high-flow combined filtration. The Nexus EAZY 220 and 220 Titanium use K+ media — the industry's most effective biological media — for demanding koi applications. Best for: serious koi keepers who want the best.

Range: $449–$3,104 · Koi-specialist filtration

Atlantic's Big Bahama skimmer and Blue Thumb's Elite skimmer series cover the mechanical surface filtration end of the ecosystem pond system. Blue Thumb's Elite line (8", 10", 15" weir widths) with natural rock lids blend seamlessly into landscape installations. Atlantic's Big Bahama handles high-volume large koi pond applications. Best for: new ecosystem pond builds, skimmer replacements, surface debris management.

Range: $398–$809 · Skimmer boxes