Pool Losing Water in Plano? How to Tell If It's a Leak or Just Evaporation

You're adding water to the pool twice a week and the level still drops. The autofill runs constantly. Your water bill jumped $40 last month. Something is wrong — but is it a leak, or is it just Texas summer evaporation doing what Texas summer evaporation does?

The answer matters because the response is completely different. Normal evaporation requires nothing but topping off. A leak requires detection, diagnosis, and repair — and the longer a leak goes unaddressed, the more damage it causes to the surrounding soil, deck, and potentially the pool shell itself. For Plano homeowners in Willow Bend, Deerfield, Kings Ridge, and the neighborhoods along Preston Road, where pools range from brand new to 25+ years old, both scenarios are common — and telling them apart takes one simple test.

How Much Evaporation Is Normal in Plano?

Evaporation rates in North Texas vary dramatically by season:

Summer (June-August): A Plano pool loses 1/4 to 1/2 inch per day from evaporation alone during peak summer. That's 1.75 to 3.5 inches per week — roughly 1,000-2,000 gallons per week for a typical 15,000-gallon pool. This is normal. It feels like a lot because it is a lot.

Spring and Fall (March-May, September-November): Evaporation drops to 1/8 to 1/4 inch per day. Still noticeable, but roughly half the summer rate.

Winter (December-February): Minimal evaporation — less than 1/8 inch per day. If your pool is losing significant water in winter, it's almost certainly a leak.

Factors that increase evaporation beyond these baselines:

• Wind exposure. Pools in open areas without windbreaks (fences, hedges, structures) lose water faster. Wind accelerates evaporation by continuously replacing the humid air layer above the pool surface with drier air.
• Heated pools. A heated pool evaporates faster because warmer water has a higher vapor pressure. A pool heated to 85°F in October can evaporate as fast as an unheated pool in July.
• Low humidity days. When relative humidity drops below 30% (common during Plano's dry summer stretches), evaporation spikes. The drier the air, the more aggressively it pulls moisture from the pool surface.
• No pool cover. A solar cover or liquid solar cover reduces evaporation by 30-50%. Most Plano homeowners don't use them, but they're effective if water loss is a concern.

The Bucket Test: The Definitive Answer

This is the only reliable way to distinguish evaporation from a leak. It takes 24 hours and costs nothing.

How to Do It

Step 1: Fill a 5-gallon bucket with pool water and set it on the top step of the pool, submerged so the bucket is sitting in the pool with the top above the waterline. Alternatively, set it on the pool deck right next to the water.

Step 2: Fill the bucket to within 1 inch of the top. Mark the water level inside the bucket with tape or a permanent marker.

Step 3: Mark the pool water level on the pool wall (use tape on the tile or skimmer face).

Step 4: Turn off the autofill if you have one. Turn off any water features (fountains, waterfalls, spillovers) — they increase evaporation and can mask results.

Step 5: Wait 24 hours. Don't swim in the pool during the test — swimmer activity disturbs the water and affects the results.

Step 6: After 24 hours, compare the two marks.

Reading the Results

Bucket and pool dropped the same amount: No leak. Both lost water to evaporation at the same rate (they're exposed to the same sun, wind, and humidity). Your water loss is normal evaporation. Top off as needed and stop worrying.

Pool dropped more than the bucket: Leak. The pool is losing water from somewhere beyond evaporation. The difference between the bucket drop and the pool drop is the leak volume. If the bucket dropped 1/4 inch and the pool dropped 3/4 inch, you're losing approximately 1/2 inch per day to a leak.

Pool dropped significantly more than the bucket (1+ inch difference per day): Significant leak. This needs prompt attention — a pool losing an inch or more per day beyond evaporation is losing 350-500 gallons daily in a typical Plano pool. That's real money on your water bill and potential structural damage from soil washout.

Making the Test More Precise

Run it twice — once with the pump on and once with the pump off.

First 24 hours: Pump running on normal schedule. Mark both levels. Measure the drop.

Second 24 hours: Pump off for the full 24 hours. Mark both levels. Measure the drop.

What this tells you:

• Pool loses more water with the pump ON: The leak is likely on the pressure side (return plumbing) — the pipes between the pump and the pool. Under pressure, these pipes push water out through any crack or failed joint.
• Pool loses more water with the pump OFF: The leak is likely on the suction side (suction plumbing between pool and pump) or in the pool shell itself. Without pressure, suction-side joints can seep, and shell cracks drain via gravity.
• Pool loses the same amount regardless of pump status: The leak is in the pool shell (a crack in the plaster, gunite, or at a fitting) — it drains by gravity whether the pump runs or not.

This pump-on/pump-off information saves time and money when you hire a leak detection professional because it narrows the search area before they start.

"But I'm Pretty Sure It's Just Evaporation..."

Before you skip the bucket test, check whether any of these are happening:

Your water bill has increased beyond what evaporation explains. Calculate your expected evaporation cost: 1,500 gallons per week × 4 weeks = 6,000 gallons per month × your water rate. If your bill exceeds this by a meaningful amount, you have a leak.

You see wet spots in the yard near the pool or equipment pad. Wet ground that doesn't dry — especially on the side of the pool nearest to the equipment pad or on a slope below the pool — indicates water escaping from the pool system underground. This isn't evaporation.

The pool deck is sinking, cracking, or separating on one side. Water from a leak washes soil away from beneath the deck and pool shell. In Plano's clay soil, this creates voids that cause settling. If one section of deck has dropped or new cracks have appeared near the pool, a leak may be washing out the supporting soil.

The pump loses prime or struggles to maintain suction. If the water level drops below the skimmer intake (even between your top-offs), the pump pulls air and loses prime. Frequent prime loss combined with faster-than-normal water loss points to a leak.

Chemical consumption has increased. A pool that's constantly being topped off with fresh water dilutes the existing chemistry. If you're adding more chlorine than usual, more acid than usual, or the water seems to resist balancing — and you're also losing water faster — the dilution from a leak-and-refill cycle may be the cause.

What to Do If the Bucket Test Confirms a Leak

Small Leak (Less Than 1/2 Inch Per Day Beyond Evaporation)

Don't panic. A small leak is not an emergency. It's costing you water and it should be fixed, but it's not causing rapid structural damage.

Check the equipment pad first. Walk the entire pad and look at every fitting, union, valve, and pipe connection. Feel for moisture. Look for mineral staining (white calcium residue from dried water drips). An equipment pad leak is the cheapest fix — often a tightened fitting or a replaced O-ring for under $50.

Check the pool shell. Look at the tile line, around each return fitting, around the light niche, at the skimmer throat, and along any visible cracks in the plaster. With the pump off and the water still, you can do a DIY dye test — squeeze leak detection dye ($8-15 at pool supply stores) near each suspected point and watch whether the dye gets pulled toward a crack or fitting.

Schedule professional detection if you can't find it. A leak detection service costs $250-500 in the Plano market and includes pressure testing of all plumbing lines, electronic listening for underground leaks, and dye testing of the shell.

Large Leak (More Than 1 Inch Per Day Beyond Evaporation)

Act quickly. A pool losing an inch or more per day is losing 350-500+ gallons daily. The water bill cost is significant, but the real concern is soil washout. In Plano's clay soil, water escaping from a leak saturates and destabilizes the soil around the pool shell and deck. This causes settling, cracking, and potentially shell movement.

Call a leak detection professional this week. Don't spend days trying to find it yourself — the ongoing water loss and potential for structural damage justify the $250-500 detection fee.

Monitor the deck and surrounding area daily for new cracks, settling, or wet spots while you wait for the detection appointment.

Where Leaks Happen Most in Plano Pools

Older Plano pools (15-25 years, built 2000-2010):

• Underground plumbing joints — PVC glue joints degrade over time, especially in Plano's clay soil where ground movement stresses buried pipes
• Skimmer body — the joint between the skimmer and pool wall cracks from soil movement and freeze/thaw cycles
• Light niche conduit — the conduit pipe behind the pool light fitting can develop leaks at the point it penetrates the pool wall

Newer Plano pools (under 10 years):

• Equipment pad fittings — connections that weren't properly sealed during construction
• Tile line — grout failure at the waterline allowing water to seep behind the tile
• Spa spillover — if the pool has a raised spa with a spillover into the pool, the spillover channel can develop cracks

The Cost of Waiting

Every week you delay fixing a confirmed leak:

• Water cost: $15-30/week for a moderate leak (1/2 inch per day)
• Chemical cost: Increased because fresh fill water dilutes your chemistry
• Soil damage: Progressive — gets worse over time, never better
• Equipment stress: The pump works harder if the water level drops repeatedly

A leak that costs $300 to detect and $500 to repair today can cause $2,000-5,000 in deck and structural damage if ignored for 6-12 months. The bucket test takes 24 hours and costs nothing. The peace of mind is worth the effort.

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Think your Plano pool has a leak? Hydra Pool Services identifies leaks, coordinates professional detection, and manages repairs across Plano, Frisco, McKinney, Allen, Murphy, Parker, and The Colony. Get it checked →