How to Plumb a Waterfall in Pool with Second Pump

Dreaming of a serene backyard oasis with the soothing sound of cascading water? Adding a waterfall to your swimming pool is a stunning upgrade—but it often demands more than your main pool pump can handle. That’s where learning how to plumb a waterfall in pool with second pump becomes essential. This dedicated setup ensures consistent water flow, reduces strain on your primary system, and keeps your waterfall looking (and sounding) perfect all season long.

Why Use a Second Pump for Your Pool Waterfall?

Many homeowners assume their existing pool pump can power both filtration and a waterfall—but that’s rarely true. According to the National Swimming Pool Foundation, over 60% of pool owners who add water features without upgrading their circulation system experience reduced filtration efficiency or premature pump failure.

A secondary pump:

• Delivers dedicated flow just for the waterfall
• Prevents overworking your main filtration pump
• Allows independent control (run the waterfall without filtering the entire pool)
• Enhances visual impact with stronger, steadier water flow

💡 Pro Tip: A waterfall typically needs 30–50 GPM (gallons per minute) for a pleasing cascade—far more than most standard pool returns provide.

What You’ll Need: Tools & Materials Checklist

Before you begin, gather these essentials:

⚠️ Always match pipe size to pump output. Undersized piping causes turbulence, noise, and energy waste.

Step-by-Step: How to Plumb a Waterfall in Pool with Second Pump

Follow this proven method used by certified pool contractors across the U.S.:

Step 1: Choose the Right Pump Location

Place the second pump below water level if possible (flooded suction) for optimal priming. If above, ensure it’s no more than 3–4 feet above the pool’s waterline to avoid cavitation. Keep it within 10–15 feet of the waterfall for efficiency.

Step 2: Tap Into the Existing Plumbing

You have two options:

• Option A (Simpler): Draw water directly from the pool (via a dedicated suction line).
• Option B (More Efficient): Tee off the pressure side of your main filter system after filtration but before the return lines.

✅ Best Practice: Use Option B—it ensures filtered water flows over your waterfall, reducing algae and mineral buildup on rocks.

Step 3: Install the Suction Line

• Run 1.5″ or 2″ PVC from the pool (or filter outlet) to the pump’s intake.
• Include a strainer basket before the pump to catch debris.
• Add a shut-off valve for maintenance.

Step 4: Connect the Discharge Line to the Waterfall

• From the pump outlet, run pipe upward to the top of your waterfall feature.
• Use 45° or long-sweep 90° elbows to reduce flow resistance.
• Install a check valve on the discharge line to prevent water from draining back when the pump turns off.

Step 5: Test & Balance Flow

• Fill all pipes with water to prime the system.
• Turn on the pump and check for leaks.
• Adjust flow using a ball valve or flow control valve until you achieve 30–50 GPM (use a flow meter or estimate by bucket test: 5-gallon bucket filled in 6 seconds = ~50 GPM).

📊 Real-World Example: A homeowner in Scottsdale, AZ installed a 1 HP Pentair WhisperFlo pump with 2″ PVC and achieved a 42 GPM flow—enough for a 4-foot-wide sheet waterfall with zero strain on their main IntelliFlo system.

Advantages vs. Disadvantages of a Dual-Pump System

🔍 Note: Energy-efficient variable-speed pumps (like those from Hayward or Pentair) can cut operating costs by up to 70% compared to single-speed models (U.S. Department of Energy).

Common Mistakes to Avoid

1. Undersizing Pipes → Causes noisy operation and weak flow.
2. Skipping the Check Valve → Leads to air locks and pump burnout.
3. Running Unfiltered Water → Stains rockwork and promotes algae.
4. Ignoring Local Codes → Some municipalities require GFCI protection or permits for added pumps.

For safety standards, always refer to the National Electrical Code (NEC) when wiring outdoor pool equipment.

FAQ Section

Q1: Can I use my main pool pump instead of adding a second one?

A: Technically yes—but only if your pump has excess capacity (typically 1.5+ HP single-speed or a variable-speed set above 2,500 RPM). However, running both filtration and waterfall simultaneously often compromises cleaning efficiency and increases wear. A second pump is strongly recommended for waterfalls wider than 2 feet.

Q2: What size pump do I need for a pool waterfall?

A: It depends on waterfall width and desired effect:

• 1–2 ft wide: ¾ HP (30–40 GPM)
• 2–4 ft wide: 1 HP (40–60 GPM)
• 4+ ft wide: 1.5 HP or variable-speed (60+ GPM)
  Always consult pump performance curves—head pressure matters more than horsepower alone.

Q3: Should the waterfall pump run 24/7?

A: No. Most owners run it 4–8 hours daily for ambiance. Continuous operation wastes energy and accelerates wear. Use a timer or smart controller (e.g., via Alexa or Pentair IntelliConnect) for scheduled runs.

Q4: Will a second pump increase my electric bill significantly?

A: Not if you choose wisely. A 1 HP single-speed pump running 6 hours/day adds ~$20–$25/month. A variable-speed pump at low RPM may cost under $8/month for the same runtime.

Q5: Can I install this myself, or do I need a pro?

A: DIY is possible if you’re comfortable with PVC plumbing and basic electrical work (GFCI circuit required). However, improper installation can void warranties or cause flooding. If unsure, hire a licensed pool contractor—many offer flat-rate waterfall add-ons.

Q6: How do I prevent calcium buildup on my waterfall rocks?

A: Use filtered water (via Option B plumbing), maintain balanced pool chemistry (pH 7.2–7.6, calcium hardness 200–400 ppm), and consider a weekly acid wash or enzyme cleaner for natural stone.

Conclusion

Learning how to plumb a waterfall in pool with second pump transforms your backyard into a luxury retreat while protecting your pool’s core systems. With the right pump, proper piping, and smart installation, you’ll enjoy the sights and sounds of flowing water without sacrificing efficiency or reliability.

Ready to create your own paradise? Share this guide with fellow pool owners on Facebook or Pinterest—they’ll thank you later! And if you’ve already installed a dual-pump waterfall, tell us your experience in the comments below. 🌊✨