Walk into any pool aisle and the number of bottles and buckets is overwhelming. The good news: most pools only need a handful of core chemicals to stay clean, clear, and safe. Everything else is a specialty product for a specific problem.
Here is the simple version for Tri-Cities pool owners, including what each chemical does and the water balance numbers to aim for.
Quick answer
Every pool owner needs 6 essentials: a sanitizer (usually chlorine), a pH adjuster, an alkalinity adjuster, a stabilizer, calcium (especially for plaster pools) and shock. Add algaecide and a test kit and you have covered almost everything a typical East Tennessee pool needs.
The chemicals every pool needs
| Chemical | What it does |
|---|---|
| Sanitizer (chlorine), Biguanides | Kills bacteria and keeps the water safe to swim in |
| pH adjuster (increaser and decreaser) | Keeps water from turning too acidic or too basic |
| Alkalinity adjuster | Stabilizes pH so it does not swing around |
| Stabilizer (cyanuric acid) | Protects chlorine from burning off in sunlight |
| Calcium hardness increaser | Prevents soft water from damaging surfaces and equipment |
| Shock (oxidizer) | Clears out contaminants and restores clarity |
| Algaecide | Prevents and treats algae growth |
Ideal water balance ranges
These are the numbers to test for and maintain in a typical residential pool:
| Measure | Ideal range |
|---|---|
| Free chlorine | 1 to 3 ppm |
| pH | 7.4 to 7.6 |
| Total alkalinity | 80 to 120 ppm |
| Calcium hardness | 200 to 400 ppm |
| Stabilizer (cyanuric acid) | 30 to 50 ppm |
Keep these in range and the water stays clear, comfortable, and easy on your liner and equipment. Let them drift and you get cloudy water, algae, irritated skin and eyes, or scale buildup.
Choosing a sanitizer
- Chlorine: the most common and affordable option, available in tablets, granules, and liquid.
- Salt systems: a salt cell generates chlorine automatically from salt in the water, so you handle fewer chemicals day to day.
- Biguanides are less popular in east Tennessee, but they are a non-chlorine approach to treating a swimming pool.
Whichever you use, the goal is the same: a steady sanitizer level that keeps bacteria in check.
Shock and algaecide
- Shock is a heavy dose of oxidizer that clears out contaminants and restores clarity. Use it after heavy use, storms, or any time the water looks dull.
- Algaecide prevents algae from taking hold and treats early growth. It is especially useful in spring and after storms, when pollen and debris feed algae.
In East Tennessee, spring pollen and summer storms are the two biggest triggers for cloudy or green water, so keeping shock and algaecide on hand pays off.
Nice to have, not essential
- Clarifier to polish slightly cloudy water
- Metal sequestrant if your fill water is high in iron or other metals
- Filter cleaner to keep your filter running efficiently
- A reliable test kit or test strips so you are adjusting based on real numbers, not guesses
A simple habit that saves money
Test before you add anything. The most common and expensive mistake is dumping in chemicals without knowing what the water actually needs, which often makes the problem worse. Adjust one thing at a time, starting with alkalinity and pH, then sanitizer.
If you would rather be sure, bring a water sample to either Isaacs supply store for free professional water testing. You will leave knowing exactly what your pool needs and nothing it does not.
Frequently asked questions
What chemicals does my pool need to start?
A sanitizer (usually chlorine), pH adjusters, an alkalinity adjuster, stabilizer, and shock cover the basics. Add algaecide and a test kit and most pools are set.
How often should I test my pool water?
Two to three times a week during peak season, and after storms, parties, or heavy use.
Why does my chlorine disappear so fast?
Often a low stabilizer level letting sunlight burn off the chlorine, or a high contaminant load that needs shock. A water test will pinpoint it.
Can I get my pool water tested for free?
Yes. Bring a water sample to the Isaacs pool supply store in Johnson City for free professional testing and product recommendations.
Stock up and test in one stop
Isaacs Pools & Spas in Johnson City and carries pool chemicals, maintenance supplies, equipment, replacement parts, and accessories, plus free professional water testing so you buy only what your pool actually needs. Serving the Tri-Cities since 1978.
