If you’re reading this, you probably have a chlorinated saltwater swimming pool, and your salt chlorine generator probably told you that the salt level of your pool is out of whack. No problem—it happens to pool owners across the world. Thankfully, adding the appropriate amount of pool salt to your pool is a straightforward process, as long as you know what variables to look out for.
In this brief guide, we’ll cover everything you need to know about pool salt, including how much pool salt you need to add to your pool, if any.
Table of Contents
What is Pool Salt?
Pool salt is basically a different type of table salt in terms of shape. It is still comprised of the two chemical elements—sodium and chlorine—but as it makes contact with your pool water, the chemicals break down into ions.
The chlorine ions will turn into hypochlorous acid, which produces less of an odor than straight-up chlorine. It also doesn’t leave as harsh of a stinging sensation on the skin and eyes as chlorine would.
Optimal Pool Salt Level
The optimal pool salt level that you should try to reach is 3,200 ppm (parts per million). The effective range is between 2,700 and 3,400 ppm. If your pool’s salinity goes over the 3,500-ppm mark, the water may have an unpleasant saltiness to it.
How Much Salt to Add
Now, how do you know how much salt to add to your saltwater swimming pool? It doesn’t take much work, provided you know how many gallons of water is in your pool (check out our Pool Volume Calculator) and the current salt level of the pool water.
Pool Salt Calculator
The formula to determine how much salt you need to add to your pool is as follows:
Salt [pounds] = Pool Volume [gallons] × 8.35 × (0.0032 – (Current Salt Level [ppm] / 1,000,000))
So, for instance, if you have a 10 × 20-foot rectangular pool with a consistent depth of 5 feet, the pool volume would be 7,500 gallons. Assuming the pool’s current salt level is 1,000 ppm—far below the average—then you would need:
137.775 pounds of pool salt = 7,500 × 8.35 × (0.0032 – (1,000 ppm / 1,000,000))
Alternatively, you can use our simple calculator to automatically calculate the amount of salt you need to add to your pool.
Testing Water Salinity
There are various ways to test the salinity of your pool water. We’ll cover each tool that can help you measure and test water salinity down below.
Digital Salt Chlorinator
If you have a digital salt chlorinator, you don’t have to purchase single-use test kits. Instead, simply head over to the digital salt chlorinator and look at its digital readout.
This device doesn’t use a sensor, but instead, it relies on complicated algorithms to get measure salinity with pinpoint accuracy. The algorithm takes voltage, cell amperes, and water temperature into account to give a final readout.
Digital salt chlorinators are the most reliable tools for measuring pool salinity.
Liquid Reagent Kit
A liquid reagent kit is an inexpensive kit that uses liquids and vials to test for salinity. All you need to do is fill the vials with a sample of your pool water and add the liquid reagent. At this point, the pool water sample should begin to change colors. Refer to the instruction manual to determine how the color corresponds with salt levels.
Digital Water Tester
A digital water tester is a handheld tool that users dip into a pool to measure salinity. Simply hold the tool in place for between 15 and 20 seconds, and the tester will display salt levels in ppm.
Pool Electronic Meter
An pool electric meter is a handheld device that’s shaped like a pen. Take the tool and the meter portion into your pool water to gauge salinity levels. Some electronic meters require taking a sample of pool water in a cup to give a more accurate reading.
Salt Test Strips
Salt test strips come in two forms—one that you can dip directly into your pool, and another that requires taking a sample of your pool water in a vial.
Most salt test strips need to be fully submerged in pool water for at least ten minutes. After that, take the strip out and compare its color against the provided color chart to determine your pool’s salinity.
What Happens If Salt Levels Are Too Low/High?
The longer you ignore improper salt levels, the quicker it will affect the quality of your pool’s water, which can affect your pool’s hardware. We don’t need to tell you that all of this put together equals a small fortune in repair costs.
One common problem pool owners face is having under-salted pool water. While a loss of salt level should be minimal throughout the swimming season, there’s a large chance that owners will have to refill their pools with fresh water to make up for any lost water due to evaporation, splash out, or spillage due to rain.
If your pool’s salinity is too low, your salt chlorine generator will produce inadequate amounts of chlorine to thoroughly clean the pool water. This, in turn, can promote the growth of algae and bacteria, which can be a pain to remove.
The good news is that if you catch the problem early on, algae will have a harder time clinging onto the walls and floors of your pool, allowing you or your robotic pool cleaner to clean everything up with minimal issues.
Now, what happens when you’ve added too much salt to your swimming pool? This isn’t as tremendous of an issue as insufficient salinity, but it does mean that you’re wasting pool salt. In addition, if the salt level is 3,500 ppm and beyond, your pool’s water will taste unpleasantly salty to the tongue.
While the solution to this problem is simple, it’s not exactly cheap. The only way to reduce salt levels is to dilute your pool water. This means partially draining your pool water and adding fresh water. This method has a high chance of throwing your pool’s salt level out of whack, so you’ll have to test salt levels and add more salt as needed. Again, our Pool Salt Calculator can help you figure out how much salt to add.
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