Last Updated: April 26, 2021

Pool Salt Calculator

Written By: Pool Care Guide

How Many Pounds of Salt Should I Add to My Pool?

You need to bring the salt levels to 3,200 parts per million (PPM). That’s the short answer. There is some wiggle room, so the number doesn’t need to be exact. You can stretch that number between the range of 2,700 to 4,000 PPM without any dramatic change to the pool’s overall health. If you go too much higher, those high salt levels can exacerbate active galvanic corrosion.

Use the salt calculator below to determine the amount of salt needed to increase salinity to ideal levels.

If you'd rather not use the calculator, you can use the following chart instead. If you know how many gallons your pool holds and the current salinity, you can use the chart to raise salinity levels to the ideal 3,200 PPM.

Pool Salt Chart (Raises to 3,200 PPM)

(Pool Gallons) →
Current Salinity↓
1,0005,00010,00015,00020,000
026 lbs.133 lbs.267 lbs.400 lbs.534 lbs.
50022 lbs.112 lbs.225 lbs.338 lbs.450 lbs.
100018 lbs.91 lbs.183 lbs.275 lbs.367 lbs.
150014 lbs.70 lbs.141 lbs.212 lbs.283 lbs.
2,00010 lbs.50 lbs.100 lbs.150 lbs.200 lbs.
2,5005 lbs.29 lbs.58 lbs.87 lbs.116 lbs.
3,0004 lbs.8 lbs.16 lbs.25 lbs.33 lbs.

1. Find Current Salinity

When you measure your pool’s current salinity level, match that number to the salinity level on the left of the chart. You can often read the number on a display on the saltwater generator. If it isn’t there, use one of the alternative options that we listed under the section “Salinity Testing Options.”

2. Find Pool Size

When you have calculated the total volume of your pool in gallons, find the correlating column in the chart. If you don’t know how to calculate your pool’s total volume, you can find the instructions to calculate your pool volume in step one on the Pool Pump Size Calculator page. 

If your pool has a consistent depth and is made of simple shapes, you can use the following formulas to calculate the volume of your pool. 

  • Square or Rectangle: Length x Width x Depth x 7.5 Gallons 
  • Circle: 3.14 x Radius² x Depth x 7.5 Gallons
  • Oval: 3.14 x Widthwise Radius x Lengthwise Radius x Average Depth x 7.5 Gallons
  • Trapezoid: ½ x (Bottom Length + Top Length) x Height

If your pool is a bit more complicated with depth changes and bizarre shapes, you will probably be best served by clicking the pool volume calculator link for more in-depth explanations. 

3. Add the Salt

On the chart, look for the point of intersection between the gallons and current salinity. The listed number tells you how many pounds of salt are required to raise the salinity to 3,200 PPM. 

How Do I Test My Saltwater Pool’s Salinity?

Most of the time, that’s actually super simple. Saltwater generators actively monitor their pool’s salt content. It is probable that you only need to look at your generator’s control unit. If you do not see the number and cycling through options doesn’t display that number, no worries. There are inexpensive testing kits.

Salinity Testing Options

There are testing kits available all over the place. There are pool sites, local pool shops, and of course, Amazon. We always recommend supporting your local shops before the websites. Amazon gets enough business as it is. However, if you do decide to use Amazon, here’s an affiliate link to the salt testing kit that we recommend. It’s a drop test kit and should provide some of the most accurate results.

Before you decide to go and purchase that product, you should know that there are other options. There are cheap disposable test strips, and there are more expensive digital readers that you can use for many years.

The product we are recommending is a middle ground between the two products. It isn’t the cheapest option, but it is reliable. It will also give you a couple of dozen tests before you need to buy more. That doesn’t sound like a lot. However, salt levels are very stable, so the kit should last for a couple of years.

Test Strips

The test strips can be a bit imprecise. Still, they can give you a ballpark estimation of your pool’s salinity. If the reading indicates that your pool’s salinity is close to the ideal 3,200 PPM, you should be able to count on that number.

Digital Readers

Digital readers can also be great tools, but they are most expensive, and some of them don’t work so well. They also need to be calibrated before every use. That isn’t a big issue as long as you remember to do it.

How to Add the Salt

Some types of pool salts are extremely pure, and others aren’t. Be mindful of how you add salt to your pool. Do not dump it into a single spot and leave it. Some of these salts have chemicals to protect them from undesirable molecular bonds, and all of them have some level of biological and mineral contamination. The salts with high levels of minerals can be extra damaging to certain pool surfaces.  

Step 1: Turn off the Chlorine Generator

Step 2: Add the salt without letting it pile up on any surfaces. Piles of pool salt can sometimes stain pool surfaces. Plaster and aggregate are the most vulnerable to these kinds of stains. If you notice any piles of salt, sweep them to disperse the salt. 

Step 3: Wait. Some say to give the salt 24 hours to dissolve before turning a chlorine generator back to its “on” state. It is up to you.

Once again, we always recommend buying from your local pool shop. If you do go through Amazon, here is a link to one of the more popular salts 

How to Lower a Salt Water Pool’s Salinity?

The answer is dilution. Once the salt has dissolved into the water, it becomes too difficult to separate. Currently, the best option is to drain the pool’s water to remove the excess salt. When enough saltwater has been drained, add more water to the pool to dilute the remaining salt. 

Because salt dissolves in water, the sodium chloride that makes up salt separates into its constituent ions of sodium and chloride. These separated ions then bind with the water molecules around them and diffuse throughout the pool. This mostly even distribution means that you can often drain a specific percentage of the water to remove a specific percentage of the salt. In other words, if you need to reduce the salinity by 20%, drain 20% of the pool’s water and replace the drained water with fresh tap water.

Questions and Answers

Which Pool Salt Is Best?

Mined Salt

Mined salt is the purest of the salt types, and that makes it the best type. When you break it down, salt is just sodium and chloride. Every one of these salt types offers the same salt. The only difference in quality is what else is shipped with the salt. 

Solar Salt

Solar Salt is the cheapest option with the most biological impurities.

When most people think of saltwater, they typically think of the ocean. With such a ready source of salt, it isn’t a mystery why some companies use the great blue wet thing as their primary source of salt.

Some companies acquire salt by diverting a stream of saltwater into a contained area. Natural forces are used to evaporate the water, and the salt is left behind. While exceptionally energy-efficient, this method collects brine shrimp, bacteria, and other biological contaminants.

Solar pool salt is a bit of a double-edged sword. It smuggles in biological pollutants, but it also generates the chloride needed to clean the pollutants it introduced. As a result, this salt type creates a greater need for chlorine. That additional work puts extra strain on the chlorine generators. If you buy purer salt, such as mined or mechanical salts, your chlorine generator will likely last longer.

Mechanically Evaporated Salt

Mechanically Evaporated Salt has the most mineral impurities.

Rather than use the power of the sun, some companies use machines to generate evaporative heat. True, this isn’t as energy-efficient as the solar option. Mechanically evaporated salt also introduces minerals from all of the physical contact with metallic machines. The additional minerals raise your pool water’s hardness which can lead to a whole host of issues. The upside to all of this is that mechanically evaporating the water destroys the brine shrimp, bacteria, and other biological components.

Do Saltwater Pools Decrease the Lifespan of Mechanical Components, Pipes, and Valves?

If you want the complete answer, you should read our article on Galvanic Corrosion. The answer is it might, but it is not likely. Most corrosion is actually due to chlorine and cyanuric acid. Salt is less corrosive than either of those. Additionally, saltwater pools use less chlorine which helps to reduce corrosion.  

Salt only becomes a major contributor to corrosion if your pool hasn’t been grounded and bonded. These are electrical terms. The first term, grounded, refers to connecting electrical currents to a pathway that leads to the earth. The second term, bonded, refers to a system of connections between the metallic components of the pool. The relationship between these metals and the nobilities of those metals are important factors in preventing galvanic corrosion. A metal with a high nobility is less reactive and less willing to part with its electrons. A metal with low nobility will quickly relinquish its precious electrons. When a metal with low nobility touches a metal with high nobility, it makes the less noble metal more susceptible to galvanic corrosion. If we want to protect these metals, we need to network all of the metals to the same sacrificial anode (A piece of metal with low nobility) that becomes the target of corrosion. This connection protects the essential pool components.

How Much Does Pool Salt Cost?

As you might expect, a range of harvesting techniques provide salts of varying levels of purity. That translates into a range of costs. On average, you can expect to pay somewhere in the ballpark of $10 to $25 for 40 pounds of salt. 

How Do I Know If a Pool Salt Product Was Mined?

Generally speaking, if the source isn’t specified, the salt has probably been mined. That’s not the case all the time. Email the manufacturer if you want to be certain. Searching through Amazon's customer Q&A is another fantastic source of information.

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