Tsurumi 50PN2.75S 1 HP Water Feature Pump – High-Flow Submersible Pump for Waterfalls, Fountains & Ponds

The Tsurumi 50PN2.75S (8PN) delivers:

• Maximum flow rate: 5,520 GPH (at minimum/zero head)
• Maximum head: 56 ft
• Best operating head range: 27–35 ft
• Required operating head range: 15–41 ft (do not operate outside this range)
• Power consumption: 1,000W / 8.7A at 115V
• Discharge: 2” FPT (female threaded)
• Cord: 20 ft (standard 115V model)

For the complete performance curve at various head heights, see the flow chart in the product gallery. The 50PN2.75S excels in high-head applications and consistently maintains strong flow at the 27–35 ft head range most common in large backyard waterfall installations.

The Tsurumi PN Series is widely used in koi pond installations for several reasons:

• 304 stainless steel housing + FRP construction: Corrosion-resistant across a wide range of water chemistries, including the slightly lower pH common in established koi ponds.
• White mineral oil: The oil chamber uses white mineral oil, which is non-toxic to fish. No petroleum contamination risk under normal operating conditions.
• Fish-safe design: The pump casing and impeller are made from FRP (Fiberglass Reinforced Plastic) and stainless steel — no brass, bronze, or copper components that could leach into pond water.
• Continuous duty: Koi ponds require 24/7 water movement for dissolved oxygen maintenance. The 50PN2.75S is specifically rated for year-round continuous operation.
• High head performance: Many koi ponds with elevated waterfalls operate at 20–35 ft of head. The 50PN2.75S maintains strong flow at these real-world installation heights.

The semi-vortex FRP impeller uses a swirling flow pattern that passes debris through the pump without the debris coming into direct contact with the impeller blades at high velocity. This design:

• Passes solids up to 0.4 inches in diameter without clogging
• Handles stringy organic material (algae, leaves) that typically wraps around conventional impellers
• Reduces maintenance frequency compared to standard direct-drive impeller designs
• The FRP (Fiberglass Reinforced Plastic) construction resists abrasion, extending impeller life even when pumping water with fine particulate

Combined with the V-Ring Seal Protector, which shields the mechanical seal from abrasive particles, the 50PN2.75S is designed for use in real-world skimmer and vault environments where the water is not perfectly clean.

Yes. The 50PN2.75S features:

• Double Inside Mechanical Seal with Silicon Carbide (SiC) faces: Silicon carbide is one of the hardest materials used in pump seals, providing exceptional wear resistance and a tight seal against leakage for an extended service life.
• Tsurumi Oil Lifter (Patent Pending): Tsurumi’s proprietary seal lubrication system. The Oil Lifter ensures the mechanical seal faces remain consistently lubricated by the oil in the seal chamber, preventing dry running of the seal even during varying operating conditions.
• V-Ring Seal Protector: A secondary protective ring that deflects abrasive particles away from the mechanical seal, further extending service life.

Together, these three seal technologies give the Tsurumi PN Series a significantly longer service life than standard single-seal waterfall pumps.

Yes. The 50PN2.75S is rated for continuous duty 24/7, year-round operation. It uses an air-filled copper-wound motor with permanently lubricated sealed ball bearings rated B-10 60,000 hours (the B-10 bearing life rating means that 90% of bearings will last at least 60,000 hours under rated conditions).

The pump also includes a built-in thermal protector with automatic reset. If the motor temperature exceeds safe limits (which can occur if the pump is starved of flow or encounters unusual load), the protector will automatically shut the pump down and restart it when temperature normalizes.

Electrical:

• Voltage: 115V / 60Hz (single phase)
• Power consumption: 1,000W / 8.7A
• Cord length: 20 ft (standard 115V model)
• Requires a properly grounded GFCI-protected 120V outlet
• Size the GFCI circuit for the 8.7A draw (a standard 15A or 20A GFCI circuit is appropriate)

Plumbing:

• Discharge: 2” FPT (female threaded)
• Connect using a 2” male NPT (MPT) adapter to standard 2” Schedule 40 PVC or flexible PVC pipe
• Add a 2” check valve on the discharge line to prevent backflow into the vault when the pump shuts off

The Tsurumi 50PN2.75S is a low-maintenance, continuous-duty pump, but these steps will maximize service life:

• Intake strainer: Inspect monthly and rinse as needed. Debris buildup on the strainer restricts flow and increases motor load.
• Winterization: In climates with sustained freezing temperatures, remove the pump from the water and store indoors to prevent ice damage to the FRP casing and mechanical seals. Store in a bucket of water to keep seals moist.
• Thermal protector resets: If the pump shuts down unexpectedly, check for debris obstruction before restarting. Allow to cool for 5-10 minutes before reset.
• Annual inspection: In hard-water areas, inspect the impeller annually for calcium scale. Clean with a dilute vinegar solution if needed.

Both models are in Tsurumi’s PN Series and share the same construction technology (semi-vortex FRP impeller, SiC mechanical seal, Oil Lifter, 304 stainless housing). The key differences are flow rate and power:

• 50PN2.25S (smaller): Lower GPH and HP — suited for medium ponds and smaller waterfall features
• 50PN2.75S / 8PN (this pump): 5,520 GPH | 1 HP | 56 ft max head | 1,000W — for large ponds, tall waterfalls, and demanding continuous-duty installations

If your installation has a head of 20 ft or less or a moderate flow requirement, the 50PN2.25S may provide a better energy-to-flow ratio. For installations with 27+ ft of head or where maximum flow at elevation is needed, the 50PN2.75S is the recommended choice.

Yes. The Tsurumi 50PN2.75S (8PN) is one of the most widely used pumps in Aquascape skimmer and waterfall filter systems. Aquascape sells this pump under their own SKU (Aquascape SKU 29495, labeled “8PN”) as a direct-fit recommendation for their larger Signature Series skimmers and BioFalls filters.

The vertical orientation of the PN Series housing is specifically well-suited to the tight chamber dimensions of Aquascape and similar skimmer designs. The 2” FPT discharge aligns with standard 2” skimmer plumbing outlets.

The Tsurumi 50PN2.75S carries a 2-Year Limited Warranty from date of purchase. The pump is also UL & CSA certified, meeting safety standards for both residential and commercial applications.

For warranty service on authentic Tsurumi products, contact Pond Pro Direct at (765) 508-4352. Retain proof of purchase for warranty claims.