Matala BioSteps-II Filter with Waterfall – Multi-Stage Pond Filtration (Up to 2,000 Gallons)

⚠ Critical pump sizing requirement: The Matala BioSteps-II handles a maximum of 1,060 GPH. Do NOT use a pump rated above 1,060 GPH — oversizing the pump will flush beneficial bacteria from the filter media faster than colonization can occur, preventing biological filtration from ever establishing. Ideal pump flow: 800–1,060 GPH. The Matala BioSteps-II Filter with Waterfall (SKU 99931W) combines a high-capacity gravity-discharge pond filter with an integrated 11-inch waterfall weir, delivering both superior multi-stage filtration and a natural cascading water feature in one unit. Rated for water gardens up to 2,700 gallons and koi ponds up to 1,350 gallons, the BioSteps-II handles a maximum of 1,060 GPH through its six Matala filter mats (2 Green, 2 Blue, 2 Gray) — providing 200 square feet of biological surface area in a rugged automotive-grade plastic housing measuring 20” × 15” × 23”. The cross-flow filtration design captures solids across the full mat volume rather than concentrating them at the inlet surface, allowing higher flow rates without channeling or premature clogging. A sloped bottom with drain plug simplifies backwash without removing the media. The internal overflow bypass protects against pump-out if media becomes blocked. The waterfall weir provides both aeration and the natural visual of water cascading over rock. Max 1,060 GPH 2,700 Gal (water garden) 11” Waterfall Weir 6 Progressive-Density Mats 200 sq. ft. Surface Area 20” × 15” × 23” Gravity Return Automotive-Grade Plastic Pond Capacity Ratings Application Max Pond Volume Notes Water Garden / Decorative 2,700 gallons Lightly stocked or no fish Koi Pond / Heavy Fish Load 1,350 gallons Koi or heavily stocked ponds Key Features & Benefits 🔀 Cross-Flow Filtration — No Bypass Channels Conventional filters push water straight down through stacked pads — creating channels that let untreated water bypass the media. The BioSteps-II’s cross-flow pattern routes water across the full width and depth of each mat, preventing channeling and increasing the percentage of water actually contacting biological surface area at every flow rate up to 1,060 GPH. 🧬 6 Progressive-Density Mats — 200 sq. ft. Bio Surface 2 Green (coarse) + 2 Blue (medium) + 2 Gray (fine) Matala mats create a progressive density filtration cascade. Coarse mats capture large solids first, protecting finer mats from premature clogging. The total 200 sq. ft. of bacterial surface area supports distinct ecological communities at each density level, improving nitrogen cycle efficiency for the full ammonia → nitrite → nitrate conversion. 🌊 11” Integrated Waterfall Weir The 11-inch waterfall spillway is factory-integrated onto the BioSteps-II housing — no external weir box, no separate plumbing run, no additional mounting bracket. Filtered water exits over the weir in a natural sheet, creating aeration through oxygen entrainment and the visual of a natural stone waterfall without the expense of a separate waterfall filter. 🛡️ Internal Overflow Bypass If filter media becomes temporarily blocked by a surge of debris, the internal bypass diverts pump flow safely through the unit rather than building back-pressure that could force water outside the filter housing. This prevents partial pond drain-down during high-debris events like autumn leaf falls — the most common cause of catastrophic gravity-filter overflow incidents. 🚿 Sloped Bottom + Drain Plug Backwash The sloped tank floor channels settled solids toward a central drain plug. Quarterly backwash (without removing any media) takes under 10 minutes: squeeze-clean the mats using the handles, open the drain plug, let accumulated sludge flush to a garden bed or waste container. No lifting, no hosing the tank externally, no media disturbance that would harm bacterial colonies. 🌡️ Automotive-Grade Plastic Construction The BioSteps-II housing is molded from the same grade of plastic used in automotive under-hood applications — rated for both sustained high heat and hard winter freezes. Unlike standard ABS pond filter housings that become brittle in prolonged frost, the automotive-grade formulation maintains structural integrity through repeated freeze-thaw cycles common in zone 5-7 winters. Technical Specifications Specification Value SKU / Model Code 99931W / BSTPII-W Pond Capacity (water garden) Up to 2,700 gallons Pond Capacity (koi / heavy load) Up to 1,350 gallons Maximum Flow Rate 1,060 GPH Recommended Pump Flow 800–1,060 GPH Waterfall Spillway Width 11” weir Filtration Method Mechanical + biological (gravity discharge) Filter Mats (6 total) 2 Green (coarse) + 2 Blue (medium) + 2 Gray (fine) Biological Surface Area 200 sq. ft. Inlet Swivel barb fitting: 3/4”, 1”, 1.25”, 1.5” Outlet 1.5” or 2” pipe (or waterfall spillway) Dimensions (L × W × H) 20” × 15” × 23” Construction Automotive-grade plastic (cold/heat tolerant) Bottom Drain Included (drain plug; optional drain valve not provided) Internal Overflow Bypass Yes — prevents pump-out during media blockage UV Clarifier Not included — optional 16W EZClear UV available separately Warranty Confirm with Matala — manufacturer warranty supported by Pond Pro Direct 💡 Optional UV upgrade: Add the Matala EZClear 16W UV Clarifier (sold separately) to the BioSteps-II inlet for integrated green-water (suspended algae) control. The unit mounts directly to the filter inlet without modifying the plumbing run. Frequently Asked Questions What is the maximum pond size for the Matala BioSteps-II Waterfall Filter? The Matala BioSteps-II with Waterfall (SKU 99931W) is rated for: Water gardens / decorative ponds: up to 2,700 gallons Koi ponds / heavy fish load: up to 1,350 gallons These ratings assume the filter is paired with a pump in the correct flow range (800–1,060 GPH) and that water is circulated continuously. Using a pump above 1,060 GPH will reduce the filter’s effectiveness by flushing beneficial bacteria faster than colonization can occur. How does the progressive density filtration work in this model? The BioSteps-II includes six Matala filter mats in three densities (2 Green coarse + 2 Blue medium + 2 Gray fine). Water flows through each mat in progression: Green (coarse): captures large particulates, fish waste, and leaf debris, protecting downstream mats from overloading Blue (medium): primary biological zone — high surface area for ammonia-converting nitrifying bacteria (Nitrosomonas) Gray (fine): polishing stage — fine particle capture and support for nitrite-converting bacteria (Nitrobacter) The cross-flow pattern routes water laterally across the full mat width rather than straight through, preventing the bypass channeling that reduces efficiency in conventional down-flow filters. Total biological surface area: 200 sq. ft. What is the recommended GPH flow rate for the waterfall spillway? For optimal filtration performance and a beautiful, consistent waterfall sheer, use a pump rated between 800 and 1,060 GPH at your installation head height. This flow range: Maximizes biological contact time within the filter mats Allows adequate settling of fine solids in the filter chamber Produces an even, full-width flow across the 11” waterfall weir Do not exceed 1,060 GPH — the filter is not designed for higher flow rates and biological filtration effectiveness will significantly decrease above this threshold. Does the BioSteps-II Filter include an overflow safety feature? Yes. The BioSteps-II includes a built-in internal overflow bypass. If the filter media becomes partially blocked by a surge of debris (e.g., autumn leaves), water is safely diverted through the bypass channel and returned to the pond via the waterfall outlet, rather than backing up and overflowing the filter housing onto your landscape. This prevents the gradual pond drain-down that can occur with gravity filters that lack overflow protection. How do I clean the BioSteps-II without harming beneficial bacteria? The BioSteps-II is designed for low-impact maintenance that preserves your bacterial colony: Squeeze cleaning: pull the mat handles upward to compress and release the filter mats, loosening trapped solids without removing the mats from the filter Drain backwash: open the bottom drain plug to flush settled sludge from the sloped tank floor — no disassembly required Critical: if you need to rinse the mats, always use a bucket of pond water, never chlorinated tap water. Chlorine kills the nitrifying bacteria that make biological filtration possible Routine squeeze-cleaning every 2–4 weeks and quarterly drain backwash is typically sufficient for most pond loads at the recommended flow rates. Why Buy from Pond Pro Direct? Authentic Matala products with manufacturer warranty support Expert filter and pump sizing guidance — call or text (765) 508-4352, Mon–Fri 9am–5pm EST Free shipping on all orders Price match guarantee on identical products 30-day return period on eligible items