Having two skimmers in your pool is quite common, and there are a few good reasons for this design.
More Thorough Skimming
The main reason for having two skimmers is that it allows for more thorough skimming of the pool surface. With two skimmers working simultaneously on opposite sides of the pool, the entire surface area gets skimmed more efficiently. This helps remove all the fine debris like dust, bugs, leaves, and other organic matter floating on top of the water before they have a chance to sink.
One skimmer alone may not be able to skim the entire surface area effectively, especially if the pool is large. Having two skimmers helps ensure no areas are missed and the skimming is uniform across the entire pool.
Balanced Water Flow
In addition to skimming, pool skimmers also serve to pull in surface water and pass it through the filtration system. With two skimmers, the water flow gets evenly distributed on both sides of the pool. This balanced flow prevents dead spots where water can stagnate due to inadequate circulation.
If there was only one skimmer, the water flow would likely be stronger on that side and weaker on the opposite side. Having two skimmers normalizes the flow for the entire pool area.
Redundancy
Having two skimmers also provides redundancy in case one skimmer gets clogged or otherwise stops working properly. With two units, if one goes down the other can continue working to skim the pool without major interruption.
This redundancy ensures more reliable and consistent skimming over the long run. If there was only one skimmer and it failed, the pool could go unskimmed for days or weeks before the issue was noticed and fixed.
Meeting Pool Codes
Many state and local pool codes require a minimum number of skimmers based on the pool size and dimensions. Having two skimmers is often the minimum to meet regulatory standards for commercial pools and residential pools over a certain size.
So in many cases, the two skimmers are a mandatory requirement for the pool to legally operate in that jurisdiction. Not having two skimmers would cause the pool to be out of compliance.
Different Types of Skimmers
Some pools may have two skimmers that are different types placed in different locations:
- Perimeter skimmer – installed along the side wall of the pool
- In-pool skimmer – installed directly in the floor of the pool
Perimeter skimmers are the most common type located on the side walls. In-pool skimmers may be added for larger pools or when needed to meet codes. Having one of each type provides comprehensive skimming across the entire surface.
Coping with High Demand
For pools that get heavy bather loads or are prone to collecting lots of debris, two skimmers may be needed simply to keep up with the skimming demand. High traffic pools like hotel, waterpark, community, or fitness facility pools often need the power of dual skimmers.
Likewise, pools with lots of surrounding trees and vegetation may get hit with a constant barrage of leaves, flowers, and other organics that two skimmers are better equipped to handle.
Accommodating Irregular Pool Shapes
Some pools have unique freeform shapes rather than basic rectangles or ovals. These irregular pool shapes may benefit from having two skimmers in specific locations to provide full coverage.
With one continuous perimeter skimmer, it may be difficult to place it such that the whole pool surface gets skimmed properly. Separating it into two strategically positioned skimmers improves the skimming for the unique pool shape.
Deck-Level vs. Wall Skimmers
Some pools combine one deck-level skimmer with one wall skimmer:
- Deck-level skimmer – installed right at the waterline, alongside the deck
- Wall skimmer – installed midway up the pool wall
The deck-level skimmer takes care of surface debris, while the wall skimmer handles missed debris that floats lower down the waterline. This one-two configuration provides complete skimming coverage from top to bottom.
New Pool Standards
On some newer pools being built today, two or more skimmers are becoming standard even on relatively small residential pools. This reflects updated pool codes, the desire for improved filtration, and recognition of the benefits provided by having multiple skimmers.
While a single skimmer may have been acceptable decades ago, standards continue to evolve. As pools are built to newer specifications, multiple skimmers are increasingly becoming the norm.
Location of the Skimmers
On rectangular pools, the two skimmers are usually installed on opposite side walls so they can work simultaneously on different halves of the pool. Round pools often have skimmers spread 180 degrees apart for balanced coverage.
On irregular shaped pools, skimmers may be placed in corners or other locations to maximize skimming for the unique footprint. The key is ensuring both skimmers are spaced out adequately to avoid overlap in their coverage zones.
How the Skimmers Connect
The plumbing for dual skimmers usually runs as follows:
- Each skimmer has its own weir and basket to collect debris
- Below the baskets, the pipes connect into a single main skimmer line
- The main skimmer line runs to a dedicated skimmer pump or the main pool pump
- From there the water enters the filter and returns clean back to the pool
So the two skimmers act as separate collectors but then combine into one skimmer system for filtration. The pump draws water through both skimmers simultaneously for efficient skimming.
Dedicated Skimmer and Main Drain Lines
On some pools, the two skimmers have fully dedicated plumbing lines that connect independently all the way to the pump and filter, rather than joining together. This helps maximize the flow from each skimmer.
Additionally, the main drain may also have its own dedicated return line. So the overall plumbing consists of two skimmer lines plus one main drain line that all connect to the pump and filter separately.
Configuring the Control Valves
When dual skimmers are installed, you can adjust the control valves to fine tune the water flow rate through each skimmer line. This allows you to direct more or less suction to each skimmer depending on their locations and coverage zones.
If one skimmer is picking up most of the debris, you can open its valve more to increase skimming from that location. The ability to control the valves grants flexibility to balance out the system.
Servicing the Equipment
With two skimmers, it’s important to divide the maintenance equally between them. You should clear out the baskets, scrub the interior walls, check the flaps, and confirm proper adjustment with equal frequency on both units. This prevents one skimmer from getting overburdened.
You should also alternate cleaning the two baskets rather than just emptying one unless the other is totally full. This ensures even wear and tear over time.
Adding a Third Skimmer
On very large or heavily used pools, some owners opt to add a third skimmer for even greater skimming power and redundancy. This third unit may be placed on a separate wall or potentially built into the stairs.
A third skimmer typically isn’t necessary for residential pools. But for massive commercial pools, busy waterparks, or Olympic-sized lap pools, the extra skimming and filtration capacity can be beneficial.
Automatic Skimmer Cleaners
Some pool owners equip their dual skimmers with automatic cleaners to maintain their performance:
- Foam skimmer socks filter out debris
- Weir jet blowers clear away floating leaves
- Self-adjusting weirs optimize skimming
These convenient options reduce the need for hands-on skimmer cleaning. Just empty out the baskets regularly and the skimmers take care of themselves.
Upgrading to Wider Piping
If a pool only has narrow 1.5″ skimmer plumbing lines, it may make sense to upgrade them to wider 2″ or 2.5″ pipes when adding a second skimmer. This reduces friction loss and allows more water flow.
Wider pipes help maximize the benefits of dual skimmers by allowing the system to handle the increased demand. Be sure the pump can also handle the added flow from two skimmer lines.
Saltwater Pool Considerations
For saltwater pools with chlorine generators, dual skimmers help avoid “dead zones” where salt concentration can get too low. By pulling water evenly from both sides, they maintain proper dispersion of salt throughout the pool.
Dead zones can lead to reduced chlorine production. So dual skimmers promote better chlorine distribution in saltwater pools.
Heated Pool Benefits
On heated pools, dual skimmers promote more even heating across the entire pool by balancing circulation. This prevents hot or cold spots that can occur if water flows disproportionately from one area.
By tempering water from opposite sides of the pool, the two skimmers create uniform heating for maximum comfort and efficiency.
Tips for Skimmer Maintenance
To keep dual skimmers performing at their best:
- Inspect baskets weekly and after heavy storms
- Clean baskets when they are halfway full debris
- Check and adjust the skimmer flaps regularly
- Verify skimmers are drawing evenly
- Watch for leaks around the skimmer body
- Seal any cracks or gaps with silicone
This preventative maintenance will extend the life of your skimmers and optimize how they function.
Cost of Installing Dual Skimmers
Typical costs for dual skimmer installation:
- Skimmer unit – $200 to $800 each
- Piping – $5 to $10 per foot
- Digging trenches & burying lines – $40 to $60 per hour
- Electrician to wire second pump (if adding) – $50 to $100 per hour
- Permits – $50 to $500 depending on location
So having two skimmers installed could cost anywhere from $1,500 to $5,000 depending on the specifics of the project.
Conclusion
Having two pool skimmers positions on opposite sides provides broader, more efficient skimming. Dual skimmers also balance water circulation, provide redundancy, and may be required by code. While one skimmer is cheaper, two skimmers give you cleaner water, improved filtration, and peace of mind knowing both sides of the pool are covered.
