If you’re a pool owner in Las Vegas, you’ve probably heard that you need to drain and refill your pool every few years. But how often should a Las Vegas pool be drained and refilled — and why is it necessary in the first place?

Unlike pool owners in regions with softer water, homeowners in Las Vegas, Henderson, Summerlin, North Las Vegas, and the surrounding valley deal with exceptionally hard water that gradually overwhelms standard chemical treatment. Draining and refilling is one of the most effective ways to reset your water chemistry and protect your pool surfaces, tile, and equipment from long-term damage.

The General Rule: Every 3 to 5 Years — But Las Vegas Is Different

The standard recommendation across the pool industry is to drain and refill your pool every 3 to 5 years. However, that guideline assumes average water hardness. In Las Vegas, where tap water calcium hardness ranges from 270 to 400 ppm, many pool professionals recommend a more aggressive schedule.

Most Las Vegas pool owners benefit from draining and refilling every 2 to 3 years, and some pools with heavy use or poor chemistry management may need it even sooner. The decision depends on several factors:

Current calcium hardness levels (above 600 ppm usually triggers a drain)
Total dissolved solids (TDS) — should stay below 3,000 ppm
Cyanuric acid (CYA) levels — stabilizer buildup that can’t be chemically reduced
Overall water balance and clarity issues that chemicals can no longer correct
Visible calcium scaling on tile, plaster, or equipment

Why Pool Draining Is Necessary in Southern Nevada

Every time water evaporates from your pool, it leaves behind dissolved minerals — mainly calcium, but also magnesium, sodium, and other compounds. As you refill with Las Vegas tap water, you’re adding more minerals to an already-saturated solution.

The Concentration Effect

Over the course of two to three years, the cumulative effect of evaporation and refill cycles can push calcium hardness above 800–1,000 ppm. At those levels, calcium is actively precipitating out of the water and bonding to every surface it touches — tile, plaster, equipment, pipes, and even your pool heater.

TDS Buildup

Total dissolved solids include everything dissolved in your water — calcium, chlorine byproducts, algaecides, sweat, sunscreen residue, and other organic and inorganic compounds. When TDS exceeds 3,000 ppm, water becomes harder to balance, chlorine becomes less effective, and water clarity deteriorates regardless of how many chemicals you add.

Cyanuric Acid Accumulation

If you use stabilized chlorine (trichlor or dichlor tablets), cyanuric acid gradually accumulates in the water. Unlike calcium, CYA can’t be removed through chemical treatment — only through dilution or draining. When CYA exceeds 80–100 ppm, it effectively locks up your free chlorine and reduces sanitization effectiveness.

How to Know When It’s Time to Drain Your Pool

Don’t wait for visible problems to appear. Regular testing gives you the data to make smart decisions. Here are the key thresholds:

Measurement	Ideal Range	Drain Threshold
Calcium Hardness	200–400 ppm	Above 600 ppm
Total Dissolved Solids (TDS)	Below 2,000 ppm	Above 3,000 ppm
Cyanuric Acid (CYA)	30–50 ppm	Above 80–100 ppm
Water Clarity	Crystal clear	Persistently cloudy despite treatment

If any of these measurements consistently exceed the drain threshold, it’s time to schedule a drain and refill. If multiple measurements are over threshold, it’s past time.

Clark County Pool Draining Regulations

Las Vegas pool owners can’t just dump pool water anywhere. Clark County and the Las Vegas Valley Water District have specific regulations about pool drainage:

Pool water should be dechlorinated before discharge — chlorine levels must be below 0.1 ppm
Water should be discharged to the sanitary sewer system (the cleanout in your yard), not into the street, storm drains, or desert washes
Some homeowners’ associations have additional rules about draining schedules and methods
Never discharge pool water onto neighboring properties or into natural drainage channels

The Southern Nevada Water Authority recommends contacting your water utility before draining to confirm discharge procedures for your specific area. Henderson, North Las Vegas, and unincorporated Clark County may have slightly different requirements.

The Pool Draining and Refilling Process

If you’re hiring a professional or doing it yourself, here’s what the process typically involves:

Test your water — confirm that calcium hardness, TDS, or CYA levels justify draining
Choose the right time — drain during cooler months (October through April) when possible. Draining in extreme summer heat can damage exposed plaster, pop the pool shell from hydrostatic pressure, or cause cracking.
Dechlorinate the water — stop chlorinating 5–7 days before draining and let sunlight naturally reduce chlorine levels below 0.1 ppm
Drain to the sewer cleanout — locate your sanitary sewer cleanout and direct the submersible pump discharge there
Never fully drain without precautions — hydrostatic pressure from the water table can lift or crack an empty pool shell. Some pools require a hydrostatic relief valve to be opened during full drains.
Refill with fresh water — fill the pool as quickly as possible to reduce exposure time
Balance the new water immediately — test and adjust pH, alkalinity, calcium hardness, and chlorine before the pool reaches operating temperature
Coordinate tile cleaning — draining is the ideal time for professional tile cleaning since the waterline is fully exposed

Partial Drain vs. Full Drain: Which Do You Need?

Not every situation requires a full drain:

Partial Drain (30–50%)

A partial drain works when you need to dilute elevated calcium or CYA levels but the water is otherwise in reasonable condition. It’s faster, less risky for the pool structure, and uses less fresh water.

Full Drain

A full drain is appropriate when TDS is extremely high, the water has become unmanageable, you need to repair or resurface the pool interior, or you want to combine the drain with professional tile cleaning and plaster inspection. Full drains carry more structural risk and should ideally be managed by a professional.

Reverse Osmosis: An Alternative to Draining

Reverse osmosis (RO) mobile pool water treatment has become increasingly popular in Las Vegas. A truck-mounted RO system filters your pool water on-site, removing dissolved calcium, TDS, CYA, and other contaminants without draining the pool.

Advantages of RO treatment include:

No structural risk from an empty pool shell
No water waste — filtered water stays in the pool
Can be done any time of year, including summer
Reduces calcium hardness, TDS, and CYA in a single treatment

The trade-off is cost — RO treatment typically runs $400–$800+ depending on pool size, compared to $150–$300 for a standard drain and refill. For larger pools or pools with expensive interior finishes, the additional cost may be worthwhile.

Frequently Asked Questions

Q: How often should a Las Vegas pool be drained and refilled?

A: Most Las Vegas pool professionals recommend draining and refilling every 2 to 3 years due to the area’s hard water. Pools with heavy use or poor chemistry management may need it more frequently.

Q: Can I drain my pool in summer in Las Vegas?

A: It’s not recommended. Extreme heat can damage exposed plaster and cause structural issues with an empty pool shell. If draining is necessary in summer, do it quickly and refill immediately, or consider RO treatment as an alternative.

Q: Where do I drain my pool water in Las Vegas?

A: Pool water should be dechlorinated and discharged into your home’s sanitary sewer cleanout. Never drain into the street, gutters, storm drains, or desert washes. Check with your local utility for specific discharge requirements.

Q: Is reverse osmosis better than draining my pool?

A: RO treatment offers the benefit of reducing calcium and TDS without the structural risk of emptying your pool. It costs more than a traditional drain and refill but is safer and can be done year-round.

Q: What happens if I never drain my Las Vegas pool?

A: Over time, calcium hardness and TDS will continue to rise, leading to persistent scaling on tile and plaster, cloudy water, reduced chlorine effectiveness, and equipment damage. Eventually, the water becomes impossible to balance chemically.

Q: Should I clean my pool tile when I drain the pool?

A: Absolutely. A drain is the ideal time for professional tile cleaning because the full waterline is exposed. Combining both services saves time and ensures your tile is fully restored before refilling.

Q: How much does it cost to drain and refill a pool in Las Vegas?

A: A basic drain and refill typically costs $150–$300 for labor, plus the cost of fill water. The exact cost depends on pool size. Reverse osmosis treatment ranges from $400–$800+. Professional tile cleaning can be added during the drain.

How Often Should a Las Vegas Pool Be Drained and Refilled?