There’s a reason pool water problems almost always come down to the same handful of things. pH out of range. Chlorine that isn’t doing its job. Alkalinity that swings all over the place. The chemistry isn’t complicated once you understand how the pieces work together, but a lot of pool owners never get that foundation, and they spend the whole summer chasing problems that could have been prevented with 15 minutes of testing a week.
Whether you’re opening your pool for the first time this spring or you’ve owned one for years and just want to stop guessing, this covers everything you need to know.
The numbers that run your pool
Pool chemistry involves a handful of parameters, but three of them drive almost every problem you’ll ever encounter. Get these right and everything else falls into place. Get them wrong and no amount of chemicals will fix your water.
| Parameter | Ideal Range | Too Low — Problems | Too High — Problems |
| pH | 7.4 – 7.6 | Acidic water, eye/skin irritation, corrodes equipment | Cloudy water, scale, chlorine loses effectiveness |
| Total Alkalinity | 80 – 120 ppm | pH swings wildly, unstable water | pH locks up, hard to adjust, scaling |
| Free Chlorine | 1.0 – 5.0 ppm | Algae, bacteria, cloudy green water | Eye/skin irritation, bleaching |
| Calcium Hardness | 200 – 400 ppm | Water pulls minerals from surfaces, etching | Scale buildup, cloudy water, equipment damage |
| Cyanuric Acid (CYA) | 30 – 70 ppm | Chlorine burns off rapidly in UV/sun | Chlorine loses effectiveness even at high levels |
| The order matters: always balance alkalinity first, then pH, then chlorine. Alkalinity is the anchor, and once it’s stable, pH becomes much easier to manage, and chlorine can do its job effectively. |
pH — an important number in your pool
pH measures how acidic or basic your water is on a scale of 1 to 14. For a swimming pool, you want to stay between 7.4 and 7.6 — slightly alkaline, which happens to be very close to the pH of the human eye at 7.5. That’s not a coincidence. Water in this range is comfortable to swim in, effective at sanitizing, and gentle on your equipment and pool surfaces.
What happens when pH drops below 7.2
- Water becomes acidic — it will start pulling minerals out of your plaster, grout, and equipment to rebalance itself
- Eye and skin irritation for swimmers
- Metal components — heaters, ladders, pump fittings — begin to corrode
- Vinyl liners can wrinkle or deteriorate faster than normal
- Your chlorine actually becomes more reactive at low pH, burning off faster and requiring more frequent additions
What happens when pH rises above 7.8
- Chlorine loses up to 80% of its sanitizing effectiveness — you can have 3 ppm of chlorine and still barely be sanitizing
- Water can turn cloudy or hazy
- Calcium begins to precipitate out of solution and form scale on your pool walls, tile, and inside your equipment
- Swimmers may notice skin and eye irritation despite normal chlorine levels
How to adjust pH
- To raise pH: Add pH Plus (sodium carbonate). Broadcast it across the deep end with the pump running. Retest after 4–6 hours.
- To lower pH: Add muriatic acid or Poollife pH Minus (sodium bisulfate). Always add acid to water and never water to acid. Add in small amounts, circulate, and retest.
| Never add acid and chlorine at the same time. Add one, circulate for at least an hour, then add the other. Mixing them in the water can create a dangerous reaction. |
Total alkalinity: your pH’s best friend
Total alkalinity (TA) measures how well your water resists changes in pH. Think of it as a shock absorber. When TA is in the right range, your pH stays stable even when rain hits the pool, swimmers get in, or you add chemicals. When TA is off, pH swings wildly and you end up constantly chasing it with adjustments that never seem to stick.
The ideal range is 80–120 ppm. Most pool professionals aim for the middle of that range as a comfortable target for Michigan pools.
Signs your alkalinity is off
- Low TA (under 80 ppm): pH bounces around unpredictably. Corrosive conditions can develop quickly. Your pool surface and equipment are at risk.
- High TA (over 120 ppm): pH becomes resistant to adjustment — it just floats upward no matter how much acid you add. Scale forms easily. Water goes cloudy.
How to raise alkalinity
- To raise: Add Pool life Alkalinity Plus. Add slowly with the pump running; it takes time to dissolve fully.
| Adjust alkalinity before you adjust pH. In most cases, getting alkalinity right will bring pH close to where it needs to be automatically. |
Chlorine: your pool’s sanitizer
Chlorine is what keeps your pool water safe to swim in. It kills bacteria, viruses, and algae, and it oxidizes contaminants introduced by swimmers, like sunscreen, body oils, sweat. Without active chlorine, a pool will turn cloudy and green faster than most people expect, especially in Michigan’s warm summer months.
Free chlorine, which is the active, available chlorine in your water, should stay between 1.0 and 3.0 ppm during swim season. Below 1.0 ppm you’re at risk of an algae bloom or bacterial growth. Above 3.0 ppm swimmers may notice eye and skin irritation, and you risk bleaching your liner or finishes.
Forms of chlorine
- Tablets (trichlor): Slow-dissolving, convenient, commonly used in floaters or automatic feeders. Contain cyanuric acid (stabilizer), if this is your main chlorine source, watch your CYA levels over the season as they will climb.
- Granular (dichlor): Fast-dissolving, good for shocking and spot treatments. Also contains CYA so use for shocking sparingly.
- Liquid chlorine: Fast-acting, no CYA, good for shocking and maintaining chlorine without raising stabilizer levels. Requires more frequent addition.
- Salt chlorine generator: Generates chlorine automatically from dissolved salt. Low-effort, consistent, and increasingly common in residential pools. Requires maintaining proper salt and CYA levels.
Shocking your pool
Shocking means adding a large dose of chlorine, typically 10 ppm or higher, to break down combined chlorine (chloramines), destroy algae, and reset your water. You should shock your pool:
- At the start and end of each season
- After heavy bather loads, like a pool party or a hot week with daily use
- After a rainstorm that dumps significant water into the pool
- Any time the water looks hazy, smells strongly of chlorine, or tests low
- Approximately every 1–2 weeks as routine maintenance during peak season
Cyanuric acid: protects your chlorine from the sun
Cyanuric acid (CYA), also called stabilizer or conditioner, is one of the most overlooked chemicals in pool care and one of the most important for Michigan pools during the outdoor season.
UV light from the sun destroys free chlorine rapidly. Without stabilizer, chlorine can lose 50–90% of its effectiveness within a few hours on a sunny day. CYA bonds with chlorine molecules and protects them from UV degradation, dramatically extending how long chlorine stays active in the water.
Getting CYA right
- Ideal range: 30–60 ppm for pools using traditional chlorine.
- Too low: Chlorine burns off so fast you can barely keep up. You’ll feel like you’re dumping chlorine constantly with nothing to show for it.
- Too high (over 90 ppm): CYA starts to impair chlorine’s ability to sanitize, even at normal levels. This is called chlorine lock — your test strip says 3 ppm but the chlorine isn’t working properly.
There’s no chemical to lower CYA. The only fix is dilution. This is why it’s important not to over-use stabilized chlorine forms like trichlor tablets as your sole chlorine source.
Calcium hardness: protects your pool surfaces
Calcium hardness measures how much dissolved calcium is in your water. This one matters a lot for pool longevity and is particularly relevant in Michigan, where source water hardness varies significantly by municipality.
- Too low (under 200 ppm): Your water becomes aggressive. It will seek calcium wherever it can find it — pulling minerals out of plaster, grout, and concrete surfaces. Over time this causes etching, pitting, and surface damage that’s expensive to repair.
- Too high (over 400 ppm): Calcium precipitates out of solution and forms scale — the white crusty buildup you see on tile waterlines, inside skimmers, and on equipment. Scale is difficult to remove and can damage heaters and pumps if left unchecked.
Raise calcium hardness with calcium chloride. Lower it by partially draining and diluting with fresh water. Test at the start of each season and after significant water changes.
How often to test and what to use
The answer to most pool chemistry problems is catching them early. Chemistry that’s slightly off is easy to fix. Chemistry that’s been off for two weeks takes time, product, and sometimes a professional visit to correct.
Recommended testing schedule
- 2–3 times per week: pH and free chlorine. These change the fastest and are your first line of defense.
- Once per week: Total alkalinity. More stable than pH but still worth checking weekly during heavy use.
- We offer free pool water testing at our Utica location. Just bring in a water sample and we’ll give you a complete read and a specific treatment plan.
- Once per month: Calcium hardness and CYA. These change slowly but matter for long-term equipment and surface health.
- Start and end of season: Full panel test including all five parameters above.
Test strips vs. liquid test kits
- Test strips: Fast and easy for quick daily checks. Not the most precise and color interpretation can vary. Good for routine monitoring.
- Liquid drop test kits (Taylor or similar): More accurate than strips. Cover more parameters. Ideal for weekly testing when you want real numbers.
| When in doubt, bring a water sample to us. We’ll test it for free and tell you exactly what you need — no guesswork, no upselling. That’s part of owning a pool from Beninati. |
The bottom line
Pool chemistry is not as complicated as it looks, it just requires consistency. Test regularly, adjust in small increments, always balance alkalinity before pH before chlorine, and don’t skip the shock treatments. Most pool problems that seem mysterious are actually just one of the same five imbalances showing up in a different way.
If you ever get stuck or want a second opinion on your water, bring a sample into our Utica location. We test water for free and will give you a straight answer on exactly what your pool needs with no guesswork and no unnecessary product push. That’s how we’ve been doing it for years and it’s why our customers keep coming back.
Here’s to a clear, safe, and enjoyable pool season.
