Understand the System Before Testing Anything
A vanishing edge pool is an engineered water balance system. The main pool overflows at one edge into a catch basin or trough. That water is then returned to the main pool via a dedicated pump and plumbing circuit. When the system is not running, water levels in the catch basin and main pool behave differently than when the overflow pump is operating.
Any evaluation of a vanishing edge pool that treats it like a standard backyard pool will produce incomplete or misleading results. You have to understand how the system is supposed to work before you can identify where it is failing.
The Component-by-Component Approach
Main pool
Evaluate the main pool shell, lights, skimmers, fittings, and plumbing independently from the overflow system. With the overflow pump off and the system at rest, watch whether the main pool holds its level or drops. This isolates the main pool from the balance system and tells you whether the main pool body itself is leaking.
The overflow edge
The overflow edge is where water deliberately spills from the main pool into the trough or catch basin. The edge itself - tile, stone, or coping along the vanishing edge - can crack, separate, or have a waterproofing failure that allows water to escape behind the visible surface rather than into the intended catch basin.
Catch basin and overflow trough
The trough or catch basin is a separate water body that collects overflow from the main pool. It has its own shell, fittings, and potential leak points. Watch the water level in the catch basin independently - if it drops when the overflow pump is off and no water is being added to it, the basin itself may be leaking.
Balance plumbing
The plumbing that returns water from the catch basin back to the main pool runs underground and includes its own suction and return lines. These can be pressure tested like any other pool plumbing line where test plugs can be seated at both ends. Lines with open termination points in the trough cannot be plugged and tested in the standard way.
The overflow pump and equipment
The overflow pump, its equipment pad, valves, and connections should be evaluated for leaks the same way any pool equipment pad is checked. Equipment leaks at this secondary pad are sometimes missed because the technician focuses only on the main equipment.
Vanishing edge pools are complexity-priced jobs. They require more time, more components to evaluate, and more systematic isolation than a standard residential pool. Do not include them in a base residential rate. Scope the job before pricing it, and make sure the customer understands that a thorough evaluation requires access to the catch basin, the overflow plumbing, and the balance equipment - not just the main pool.
Common Mistakes on These Jobs
- Treating the main pool and the overflow system as one water body when they need to be evaluated separately
- Pressure testing plumbing without first identifying which lines serve the main pool and which serve the overflow circuit
- Ignoring the catch basin because it is less visible than the main pool
- Assuming the overflow edge itself is watertight because the main pool shell appeared sound
- Quoting the job at a residential rate without understanding the scope
Learn to Evaluate Complex Water Systems Systematically
LBA teaches the component-by-component approach to vanishing edge pools and other complex systems - so nothing gets missed and nothing gets assumed.
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