You’re not alone if you wake up each morning to find your swimming pool water level noticeably lower. One of the most common complaints among pool owners is, “My pool is losing water overnight.”
While evaporation can cause minor water loss, significant overnight drops usually point to something more serious—a leak.
The Most Likely Cause: A Suction-Side Plumbing Leak
Swimming pools typically lose more water at night when the pump is off because of a suction-side plumbing leak. This includes lines like the skimmer or main drain lines, which carry water from the pool to the pump.
When the pump is running, suction keeps these lines under negative pressure, which can temporarily slow or stop the leak. Once the pump shuts off overnight, the water can escape freely through the break in the suction-side plumbing line.
Signs of a Suction-Side Leak
If your pool is losing water overnight, look for these telltale signs of a suction-side plumbing leak:
- Water Loss Occurs Mainly at Night When the Pump is Not Running: A key indicator that your plumbing leak is on the suction side.
- Air Bubbles in the Pump Basket After Startup: If air enters the lines through a leak, it will often collect in the pump and cause visible bubbles at startup.
- Pump Loses Prime or Struggles to Stay Primed: A leak in the suction line can allow air to enter, causing the pump to lose suction and making it difficult to maintain proper flow.
Other Possible Causes to Consider
While suction-side leaks are a leading cause, here are a few additional possibilities for overnight water loss:
- Leaking Skimmer Throat or Housing: A leak in the skimmer throat or the skimmer housing should be leaking all the time. However, water loss could be most noticeable in the morning. A leak in the skimmer throat or housing would cause the water level to stop going down once it reached the bottom of the pool tile.
- Structural Cracks Below the Waterline: Cracks in the pool shell or PVC fittings should leak continuously but may be most noticeable in the morning.
- Leaky Main Drain: A compromised main drain or plumbing line can cause steady overnight leaks, especially in older pools.
What You Can Do
If your pool loses more than ¼ inch of water overnight, you’re likely dealing with more than evaporation.
To confirm the source of the leak, a professional leak detection service should conduct a full inspection, including pressure testing of your plumbing lines and dye testing of your pool shell.
Call Precision Leak Detection
If you’re located in Palm Beach Gardens, Florida or anywhere in Palm Beach County and your pool is losing water overnight, contact Precision Leak Detection.
We specialize in pinpointing and diagnosing all swimming pool leaks—from suction-side plumbing issues to structural cracks and beyond. Our expert team uses state-of-the-art equipment to identify the source of the problem quickly and accurately.
Please schedule your appointment today and let us help you stop the leak before it worsens.
