That’s where draining comes in. Not the most exciting part of pool ownership, sure—but one of the most important.
Let’s just get this out of the way: pool water doesn’t last forever. It’s not a magical self-cleaning potion that resets every time the chlorine goes in. Eventually, the water gets tired. It gets full. Not with leaves or bugs, but with dissolved stuff—like calcium, salts, stabilizers, and all the bits and pieces left behind from sunscreen, sweat, and the occasional questionable cannonball guest.
In the pool business, that stuff is called Total Dissolved Solids (TDS). It builds up over time, and when it reaches a certain level, it starts to cause trouble. It’s like when your favorite pot of gumbo has been reheated one too many times—eventually, it just doesn’t taste right. The chemistry gets harder to balance, the chlorine stops working as well, and surfaces can start to stain or scale.
Now, as for how often to drain a pool? The general answer is every 3 to 5 years. But before anyone hauls out a pump and starts emptying the backyard, let’s cover the “why” in more detail.
Why Drain Pool Water in the First Place?
It’s not just about having clean water. Draining is about resetting the chemistry so the water can actually work again. Over time, the buildup of things like:
- Calcium and other minerals
- Cyanuric acid (if stabilized chlorine is used regularly)
- Salts from saltwater generators
- Debris breakdown and organics
…makes it harder to keep the water balanced. Eventually, the sanitizer gets sluggish, algae shows up more often, and filters work overtime just trying to hold the line. No one wants to swim in a pool that’s chemically exhausted. Even if it looks okay on the surface, the water might be fighting a losing battle underneath.
When to Know It’s Time
Most pool owners won’t drain their pool on a set calendar like it’s a dental cleaning. Usually, something gives it away:
- The chlorine isn’t holding
- Algae keeps coming back for a visit
- The water looks cloudy or feels “off”
- Stains or scale start creeping up the tile line
- The pool starts to smell more like a gym locker than a swimming hole
Those are signs the water’s past its prime. It’s not misbehaving on purpose—it’s just reached capacity. There’s only so much chemistry one body of water can take before it needs a fresh start.
Surface Type Matters
Pools aren’t one-size-fits-all when it comes to draining. Concrete and plaster pools usually need more frequent draining because their surfaces are porous and prone to absorbing minerals. They can also start to show surface issues like etching or scaling when chemistry gets out of control.
Vinyl and fiberglass pools are a little less needy in this department, but that doesn’t mean they’re off the hook. TDS still builds up, and draining every few years helps maintain proper function and appearance. Just because a pool can go longer doesn’t mean it should.
Groundwater, Weather, and Doing It Right
Now, draining isn’t something to take lightly. Do it wrong, and the whole pool can pop right out of the ground like a surprise lawn ornament. That’s why timing matters. Avoid heavy rain, check the groundwater table, and make sure the drainage area is legal and safe—nobody wants to be the neighbor responsible for sending 20,000 gallons downhill into someone’s garage.
Professional equipment helps, too. Submersible pumps, controlled flow, and the right timing all make sure the job gets done safely. And once it’s drained? That’s the golden hour for giving the pool a deep clean. Tiles, surfaces, fittings—all easier to inspect and refresh when the water’s out of the way.
What If Full Draining Isn’t an Option?
Sometimes the schedule, the cost, or the weather makes a full drain a no-go. In those cases, partial draining (say 30–50%) can help. It won’t fix everything, but it can lower TDS and dilute excessive stabilizer or calcium. Think of it like changing half the oil in a car—not ideal, but better than nothing.
Final Thought: It’s Maintenance, Not Emergency
Draining shouldn’t be a panic move. Done regularly and with intention, it helps preserve equipment, protect surfaces, and make pool care easier year-round. And really, it gives the water a well-deserved break after years of filtering, sanitizing, and keeping everyone cool all summer.
So next time the chlorine won’t hold, or the algae throws a pool party without an invite, it might be time to think beyond more chemicals. Sometimes, the best solution is as simple as starting fresh.
Just remember: water gets tired, too. Give it a break every few years, and it’ll thank you by doing its job better. And if unsure? Ask a pro before pulling the plug—because an empty pool isn’t always as harmless as it looks.
