If you own a saltwater pool, you know salt is the lifeblood of your pool.
Not enough salt and your saltwater chlorinator will struggle to produce enough chlorine to keep your water sanitized. Too much salt and your pool will taste like the Atlantic Ocean.
This is what makes the salt level so critical, and why we’re going to show you how to test salinity in your pool, step by step.
What’s the Ideal Salt Level in a Pool?
The ideal salt level for a pool is generally between 2700 and 3400 parts per million (ppm).
With that being said, the ideal range can differ from one salt generator to the next, so check your user manual as the recommended range may be considerably higher.
On that note, it’s a good idea to aim slightly higher than your target level since you will lose salt over time, be it through things like rain dilution, leaks, splashout, or backwashing.
Lastly, it doesn’t matter what your test results say if your saltwater generator isn’t happy with the salinity level, as it will stop making chlorine. Ultimately, if the low salt light is flashing on your generator, you need to add more salt.
How Accurate is Your Salt System Reading?
The reading on your saltwater generator isn’t very accurate.
The reading given by your generator is determined by running a small electrical current through your pool water to gauge its conductivity.
While this can sometimes give you a close enough measurement of salt, the conductivity of the water isn’t only dictated by the salt level or salinity, but also by factors like water temperature.
Since there are other variables involved in this reading, it’s impossible to solely rely on what your salt system tells you, which is why testing is still necessary.
Test Strips or Drops to Measure Salt in a Pool?
It’s well established that test strips aren’t quite as accurate as liquid test kits, even if they are easier and more convenient.
Fortunately, that applies more to testing basic parameters like pH, alkalinity, free chlorine, cyanuric acid, and calcium hardness.
One reason is that you need a separate test strip or liquid test kit to measure salinity, as multi-purpose pool test kits don’t include salinity. These dedicated tests are inherently more accurate, which makes the strips more viable.
Another reason is the lesser importance placed on salt level because you have a wider range to play with. While you could spend a little more money and time on getting a more precise reading, a roundabout reading is often good enough.
Finally, there’s added complexity around using drop kits to perform a salt level test because the instructions differ slightly from regular drop tests, increasing the likelihood of user error.
Overall, when it comes to testing salt levels in a pool, salt test strips are a better choice for most pool owners.
How to Test Salt in a Pool with Test Strips
The steps below are based on the popular AquaChek salt testing strips, though the process should be very similar to other salt strips.
Here’s how to do a salt level test in a pool:
1. Take a Small Sample from Your Pool
Unlike traditional test strips, these strips need to be submerged in your pool water for minutes rather than seconds.
The best way to do this is to take a small container or cup and fill it with about an inch of water from your pool, preferably from a well-circulated patch of water (near but not directly in front of your return jets).
2. Grab a Salt Testing Strip from the Bottle
Next, take a strip from the container or bottle, ensuring you only touch the white part of the strip when handling.
While these aren’t as vulnerable to outside exposure (such as humidity in the air), you still need to make sure the bottle is closed tightly between uses to extend the life of your salt strips.
3. Submerge the Strip in the Water Sample
Gently place the strip in your cup of water, with the white part upright.
The red line running up the testing strip only needs to be partially submerged in the water, so don’t worry if it seems too shallow.
4. Wait a Few Minutes for it to Soak
The salt test strip needs to sit in the water for around 4-5 minutes.
You’ll know it’s done when the yellow band across the top of the strip turns a deep shade of red (almost black). As soon as this band stops changing color, you can go ahead and pull the strip out of the water.
5. Check the Level on the Strip
At this point, you will notice an orange line running up the strip where a solid red color used to be.
The point at which this orange line stops is your reading, so look carefully and note the markings on the strip itself. You will need this number to get your true salt level reading in the next step.
6. Convert to PPM on the Bottle
On the back of the bottle or container that houses your strips, you’ll notice a conversion chart.
Here, you can find the reading you just took from your strip and check the corresponding salt value in parts per million (ppm). This will be the exact salt level in your pool according to the results.
7. Discard the Strip
Finally, be sure to discard the strip after use.
All pool testing strips are single-use, and this includes salt strips. Not only will the strips not respond to water after the first time, but the colors indicating your results will slowly fade as they begin dry out.
How Often Should You Test Salinity?
You should test the salt level in your pool every month to every three months depending on the amount of water loss you experience.
Checking your salinity isn’t required as often as other tests because your salt level is unlikely to change dramatically in a short period of time.
While some salt is lost through splash out, rain dilution, overflowing water, leakages, and filter backwashing, your salinity isn’t going to be too low after just a few weeks – especially if you were already a little over the ideal range.
And while your saltwater generator uses salt to create chlorine, that chlorine reverts back to salt once it breaks down, meaning the chlorine creation process alone will never put you in a salt deficit.
Testing the salt level in your pool isn’t difficult or time-consuming, and only requires a few minutes to perform a test every few months.
The reward for doing so is both a well-functioning saltwater generator and healthy, well-sanitized water that will not only make swimming more enjoyable but will also prolong the life of your pool.