Aqua Medic
Pool Chemistry 101
As the Texas sun warms up and spring bursts into full bloom, it's officially "pool season" again. Before you dive back into backyard bliss, it's important to remember: every pool and backyard is a little different.
Think of your pool like a living ecosystem. Its balance is influenced not just by your equipment and chemicals, but also by the sunlight it soaks up, the trees and plants around it, and how often (and how many) people are splashing around. Managing your pool isn’t just about keeping it blue — it’s about keeping it healthy.
First, a quick refresher: the three basics of pool care are:
- Circulation — your pump and filter need to run properly to move and clean your water.
- Cleaning — brushing, skimming, and vacuuming keeps debris (and algae!) at bay.
- Chemistry — balancing your water’s chemical levels to keep it safe and clear.
Today, let’s zero in on that last one: chemistry. Here are the key players you should know this season.
Free Chlorine
Free chlorine is your pool's first line of defense. It keeps the water sanitized by killing bacteria, viruses, and algae. The trick? You need enough "free" chlorine — meaning chlorine that is active and available — not just "total" chlorine that's been used up already.
Keeping your free chlorine between 2.0 and 4.0 ppm (parts per million) is ideal for most pools. Regular testing is key, especially after heavy use or storms.
Alkalinity
Alkalinity acts as a bodyguard for your pH levels. When your total alkalinity is in balance (typically 80-120 ppm), it helps prevent wild pH swings that can make your water cloudy or irritate swimmers' eyes and skin.
Think of alkalinity as the "shock absorbers" of your water chemistry.
pH Scale
Speaking of pH, it measures how acidic or basic your water is. A safe swimming range is 7.2 to 7.8 on the pH scale. If your pH is too low (acidic), it can corrode your equipment and sting swimmers. Too high (basic), and it reduces chlorine's effectiveness and can lead to cloudy water.
Keeping pH balanced keeps your entire pool system happier.
Total Dissolved Solids (TDS)
TDS represents the total amount of dissolved materials — minerals, salts, metals, organic matter — in your pool water. Over time, TDS naturally rises. High TDS can make water look dull, cause scaling, and interfere with sanitation.
If your TDS climbs too high (usually over 1,500-2,000 ppm for freshwater pools), you may need a partial drain and refill.
Salt System Pools: A Special Note
If you have a saltwater pool, congratulations — you're swimming in a softer, more skin-friendly experience! But salt systems aren't "maintenance-free."
Salt cells generate chlorine from salt, creating a chlorine gas. Salt pools tend to experience rising pH over time because of the byproducts of the salt-to-chlorine conversion process. So you're still managing chlorine, pH, and alkalinity — just in a different way. Keeping a close eye on your pH and alkalinity levels is critical. Regular acid additions and monitoring your stabilizer are key to keeping your salt system balanced and your equipment happy. (more about salt systems)
Texas Hard Water: What You Need to Know
Here in Texas, "hard water" is a way of life. Thanks to all the limestone in our soil, tap water already comes loaded with calcium and minerals. When that calcium level gets too high in your pool, you’ll notice it: white, chalky buildup around your tile line and water features.
Monitoring your calcium hardness (ideally 200-400 ppm) helps prevent unsightly scaling and protects your equipment.
Stabilizer: Sunscreen for Your Chlorine
When you fill a brand-new pool or do a major refill, adding stabilizer — also known as cyanuric acid — is crucial. Think of stabilizer as sunscreen for your chlorine. It protects chlorine from burning off quickly under the Texas sun.
But, just like too much sunscreen can block your pores, too much stabilizer can "lock up" chlorine and make it ineffective. Aim for 30-50 ppm — and remember, you should only add it when needed (and sparingly).
Want help mastering your pool’s unique chemistry?
Aquamedic offers Pool School sessions for homeowners to get hands-on with their specific pool equipment and water needs. We’ll walk you through everything from reading your test kit to fine-tuning your backyard oasis for a season full of stress-free swims.
Ready to make this your best pool season yet? Contact us today to schedule your Pool School session!
