How To Plumb A Pool With Two Skimmer Baskets

Are you struggling with uneven water flow or debris accumulation in one corner of your pool? Many homeowners face this challenge when designing or renovating their backyard oasis, often wondering how to plumb a pool with two skimmer baskets to ensure optimal cleanliness. Proper plumbing is the heart of your pool’s circulation system, and getting it right from the start saves you time, money, and frustration down the road. In this guide, we will walk you through the essential steps, best practices, and expert tips to achieve a perfectly balanced dual-skimmer setup.

Why Use Two Skimmers Instead of One?

Before diving into the pipes and fittings, it is crucial to understand why dual skimmers are often recommended for larger pools. A single skimmer may struggle to keep up with surface debris in pools exceeding 400 square feet. By installing two skimmers, you create a wider net for catching leaves, bugs, and oils before they sink.

According to industry standards, the placement of skimmers should account for prevailing wind directions. If your pool is located in an area with consistent breezes, positioning two skimmers allows you to capture debris pushed by the wind more effectively than a single point of suction. This redundancy also ensures that if one skimmer gets clogged, the other continues to maintain water circulation, protecting your pump from running dry.

Essential Tools and Materials

To successfully plumb your pool, you need the right equipment. Using substandard materials can lead to leaks and costly repairs later. Here is a checklist of what you will need:

• PVC Pipes: Schedule 40 PVC is the standard for residential pools. For most residential setups, 2-inch diameter pipes are recommended for main suction lines to minimize friction loss.
• Fittings: Elbows (90-degree and 45-degree), couplings, and tees.
• Skimmer Bodies: Two high-quality ABS or PVC skimmer housings compatible with your pool wall material (concrete, vinyl, or fiberglass).
• Primer and Cement: Specifically designed for PVC pressure applications.
• Teflon Tape: For threaded connections.
• Pipe Cutter and Deburring Tool: For clean, precise cuts.

Pro Tip: Always check local building codes. Some municipalities in the US require specific backflow prevention devices or anti-entrapment compliant drains alongside skimmers.

Step-by-Step Guide: How To Plumb A Pool With Two Skimmer Baskets

Plumbing is both an art and a science. Follow these detailed steps to ensure a leak-free and efficient installation.

Step 1: Determine Skimmer Placement

The location of your skimmers is critical. They should be placed on the side of the pool where the wind typically blows debris. For rectangular pools, place them on the long walls. Ideally, position them so they are not directly opposite each other if the pool is very wide, but rather staggered to cover different zones.

Ensure there is at least 18–24 inches of clearance from any return jets to prevent short-cycling (where filtered water is immediately sucked back into the skimmer without circulating through the whole pool).

Step 2: Trenching and Pipe Routing

Dig trenches from the skimmer locations to the pump pad. The depth should be below the frost line if you live in a colder climate to prevent pipe bursting. For most southern US states, a depth of 12–18 inches is sufficient, while northern states may require 36+ inches.

• Slope the pipes: Ensure a slight slope toward the pump to aid in drainage during winterization.
• Avoid sharp bends: Use two 45-degree elbows instead of one 90-degree elbow whenever possible. This reduces turbulence and maintains water velocity.

Step 3: Connecting the Skimmers to the Main Line

This is the core of learning how to plumb a pool with two skimmer baskets. You have two primary options for connecting the skimmers to the pump:

1. Independent Lines: Each skimmer has its own dedicated pipe running all the way to the pump. This is the preferred method for professional installations as it allows for individual valve control.
2. Combined Line: The two skimmers merge into a single pipe via a tee fitting before reaching the pump. This is cheaper but offers less control over suction balance.

Recommendation: Go with independent lines. Run two separate 2-inch PVC pipes from each skimmer to the equipment pad.

Step 4: Installing Valves for Balance

At the pump pad, install ball valves on each suction line before they connect to the pump’s intake. This is non-negotiable for a dual-skimmer setup.

Why? Because water follows the path of least resistance. If one skimmer is closer to the pump, it will naturally suck more water. By using ball valves, you can manually restrict the flow on the “easier” line to force more suction to the farther skimmer. This ensures both skimmers are working equally hard.

Step 5: Priming and Gluing

Clean all pipe ends and fitting interiors with purple PVC primer. Apply a generous layer of PVC cement to both surfaces. Insert the pipe into the fitting with a quarter-turn twist to spread the cement evenly. Hold for 15–30 seconds to set.

• Temperature Check: Perform this work when temperatures are between 50°F and 90°F (10°C–32°C). Extreme cold prevents proper curing, while extreme heat causes the cement to set too quickly, potentially leading to weak joints.

Step 6: Pressure Testing

Before backfilling the trenches, you must test for leaks. Cap off the open ends and use a pressure tester to pressurize the lines to 20–25 PSI. Let it sit for at least 30 minutes. If the gauge drops, you have a leak. Find it, fix it, and retest. Never skip this step.

Understanding Hydraulic Balance

Balancing your pool’s hydraulics is key to longevity. When you have two skimmers, you want the water level in both to drop at the same rate when the pump is running. If one skimmer pulls air while the other is full, your balance is off.

Adjust the ball valves at the pump pad:

1. Open both valves fully.
2. Observe the water flow in the skimmer throats.
3. Partially close the valve on the skimmer with stronger suction.
4. Repeat until both skimmers exhibit similar vortex strength.

For more detailed information on fluid dynamics in piping systems, you can refer to general engineering principles on Wikipedia’s Page on Fluid Dynamics.

Common Mistakes to Avoid

Even experienced DIYers make errors. Here are the top pitfalls:

• Undersized Piping: Using 1.5-inch pipe for long runs creates excessive friction, straining your pump. Stick to 2-inch for main suction lines.
• Too Many Elbows: Every 90-degree turn adds resistance. Plan your route to be as straight as possible.
• Ignoring Air Leaks: Even a tiny pinhole on the suction side can cause your pump to lose prime. Ensure all connections are airtight.
• Skipping the Union: Install a union fitting before the pump intake. This allows you to remove the pump for service without cutting pipes.

FAQ Section

Q1: Can I connect two skimmers to one 1.5-inch pipe?

A: It is not recommended. Two skimmers generate significant water demand. Combining them into a single 1.5-inch line will restrict flow, causing cavitation and reducing the efficiency of your filtration system. Use separate lines or a larger main trunk line (2.5 or 3 inches) if combining.

Q2: How deep should the plumbing trenches be?

A: This depends on your location. In warm climates like Florida or California, 12–18 inches is usually sufficient. In colder regions like New York or Michigan, you must bury pipes below the frost line, often 36–48 inches deep, to prevent freezing and cracking.

Q3: Do I need a valve for each skimmer?

A: Yes. Individual ball valves for each skimmer line are essential for balancing the suction. Without them, you cannot adjust the flow distribution, leading to one skimmer doing all the work while the other remains stagnant.

Q4: What size PVC pipe is best for pool skimmers?

A: For residential pools, 2-inch Schedule 40 PVC is the industry standard for suction lines. It provides an excellent balance between flow capacity and cost. 1.5-inch pipe may be used for very small plunge pools, but 2-inch is safer for future-proofing.

Q5: How do I know if my skimmers are balanced?

A: Turn on the pump and look at the water surface in both skimmers. You should see a gentle, consistent vortex in both. If one is swirling violently while the other is calm, adjust the ball valves at the pump pad until the activity looks similar in both.

Q6: Can I add a second skimmer to an existing pool?

A: Yes, but it requires cutting into the pool shell and running new underground plumbing to the equipment pad. This is a major renovation project. It is often easier to install a robotic skimmer or a surface skimmer accessory if you want to avoid extensive plumbing work.

Conclusion

Learning how to plumb a pool with two skimmer baskets is a valuable skill that enhances your pool’s performance and cleanliness. By using independent 2-inch lines, installing ball valves for balance, and carefully planning your skimmer placement, you create a robust circulation system that stands the test of time. Remember, patience during the pressure testing phase saves you from nightmares later.

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