How to Balance Pool Water in Las Vegas

Las Vegas pools start with hard water and only get harder. Every time the sun evaporates water and the hose tops it back up, the minerals stay behind. That's why balancing pool water here takes a little more attention than it does in most places. The good news is that you don't need to guess. Enter your test strip readings in our free Vegas Water Check pool chemical calculator and it tells you what to add, and how much, for your pool size.

Why Las Vegas water is hard on pools

The Las Vegas Valley Water District's 2026 water quality summary lists total hardness at 280 ppm (about 16 grains per gallon), pH at 7.8 and total dissolved solids at 591 ppm. Your fill water already leans toward scale before you add a single chemical. As water evaporates and gets replaced, calcium builds up over time, and that's what leaves white crust on tile and rough spots on plaster. (More on that in our post on high calcium in Las Vegas pools.)

The target ranges

The pH, alkalinity and calcium ranges come from Maryland's public pool code (COMAR). The stabilizer limit is from the CDC Model Aquatic Health Code. Our chlorine target is a little stricter than the CDC minimum of 2 ppm, which suits our sun. Want to see where your pool stands? Check your readings in Vegas Water Check.

What LSI means, in plain English

The Langelier Saturation Index (LSI) is one number that combines your pH, alkalinity, calcium and water temperature. A negative number means the water wants to pull calcium out of your plaster. A positive number means it wants to drop calcium as scale. Close to zero is balanced. The calculator works it out for you, and adjusts alkalinity for stabilizer so the number stays honest.

Fix things in the right order

1. Alkalinity first. It buffers pH, so fixing pH before alkalinity just makes it drift again.
2. Then pH. Add about half the dose, let it circulate, and retest.
3. Then calcium. You can raise it with calcium chloride, but the only way to lower it is to dilute it with fresh water.
4. Then chlorine, matched to your stabilizer level.

Add one chemical at a time, let the pump run, and retest before adding the next. Never mix chemicals together, and the label on your product takes precedence.

Chlorine tablets add stabilizer

Three-inch trichlor tablets are easy, but each one adds stabilizer too. The EPA-registered label rate is one 8 oz tablet per 10,000 gallons a week, in a floater or feeder. By our math, that adds about 13 ppm of stabilizer a month. Stabilizer doesn't evaporate or break down, so high CYA only comes down with a partial drain and refill. If your readings keep showing high calcium or stabilizer, read when to drain and acid wash.

How to figure out your gallons

Every dose depends on pool size. The EPA label gives these formulas (measurements in feet):

• Rectangle: length × width × average depth × 7.5
• Oval: long side × short side × average depth × 5.9
• Round: diameter × diameter × average depth × 5.9

For freeform pools, use the size helper in the calculator and treat the result as an estimate.

When to call a pro

Call a Licensed pool pro if calcium or stabilizer is high, if the water stays cloudy or green, if you see scale or etching, or if you're not sure how to handle the chemicals safely. Our weekly pool service keeps your chemistry in range all year.

Common Questions

What is the ideal pH for a pool in Las Vegas?

Aim for 7.4 to 7.6. Anywhere from 7.2 to 7.8 is acceptable. Las Vegas tap water comes in around pH 7.8, so most pools here need acid now and then.

Why does my Las Vegas pool get scale?

Our tap water is hard, and evaporation concentrates the calcium over time. A positive LSI means the water is likely to drop scale. Check yours free in Vegas Water Check.

How do I lower calcium or stabilizer in my pool?

Neither one can be removed with chemicals. Both only come down with a partial drain and refill with fresh water.

Serving pools in Henderson, Summerlin, Green Valley, Anthem, Seven Hills and Silverado Ranch.