how much salt to add to pool at startup

Posted by Robert J. on 12/9/2019 to Common Questions

The process of setting up your saltwater chlorine generator is already very easy, and once you've done that, you're already completed the "hardest" part! The simplest step of setting up your new salt water system comes next- adding the salt.

Whether you're in the process of installing or converting your pool, or you haven't yet purchased a saltwater chlorine generator, or maybe you're just looking into what supplies you'll need to buy, you probably already know that you need to buy the actual salt to put in the pool. But how much? And what kind?

We've put together an easy guide to tell you what you need to know about how much you'll need, how to put it in your pool correctly and exactly what kind you'll need for your pool, as well as some tips and tricks to help you along the way.

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Determine your Optimum Salinity Level

Depending on the manufacturer, salt pool systems can work in salt levels from 3000 to 5000 parts per million (ppm).

The first step you'll want to take is checking your salt chlorinator's owners manual . There are a bunch of popular brands on the market, and many of them vary in the optimal salinity range that is recommended.

If you haven't yet bought yours, check it out before you buy so you can get a head-start in knowing how much you'll need to purchase and to determine which system is best for your pool's size.

Salt pool systems all work on different salt levels from 3000 to 5000 ppm, or parts per million, depending on the manufacturer. Since the majority of chlorinators operate between 3000 and 4000 ppm, in this example we'll use the target level of 3500 ppm which will apply to most people.

Check for Any Existing Salt Levels

The next step is to figure out how much salt might already be in the pool. If you have a new pool, you likely don't have a significant salt level present , but sometimes it can be possible that the pool naturally acquires around 500 ppm over time.

If the pool has been around awhile, it's certainly possible salt has been added to the water in the past , so either way it's always a good idea to check just in case so that you don't accidentally end up making your salinity level too high.

You'll want to purchase some salt water test strips so you can test the current salinity of your pool's water. Also, most pool stores offer free water testing services, so if you want to save money and also get a more accurate result, you can always choose this option as well. You can also get fast & accurate digital testers for your pool as well.

Determine Pool Size & Quantity of Salt Needed

The next step is figuring out how many gallons of water are in your pool. If you're not sure, you can use the following formulas to calculate an estimate, depending on the shape of your pool. (length, width, and depth are measured in feet)

For this example, our goal salinity is 3500 ppm and the pool has zero existing salinity. In that case, You'll need to add 30 lb of salt for every 1000 gallons of water.

Therefore, if you have a 20,000 gallon pool and want to determine how much salt you'll need to buy, you would use the formula "30/1,000 x 20,000", which equals 600. Meaning, the pool would require approximately 600 lb of salt.

bags of salt to convert swimming pool to a saltwater chlorine generator

So, you've installed your saltwater system or you're in the process of buying all your materials for your installation, and now it's time to buy the most important aspect- the salt itself!

You can find pool salt and water softener salt at any big-box, home improvement or pool store , but if you're looking to save even more money , plain regular water softener salt is less expensive.

It's virtually the exact same thing, and ranges from around $5-$7 for a 40 lb bag- which is the typical size you'll find at most stores! Using our previous example, we would need to buy about 15 bags of salt for the 20,000 gallon pool.

A few extra tips:

Always use non-iodized salt that is at least 99.8% pure sodium chloride (NaCl)
Avoid any salt with anti-caking agents
Do not get anything that has any "special formula" additives (ex: "anti-rust"), as they can cause staining in your pool.

Adding the Salt

If you've already installed your Salt Water Chlorine Generator, make sure you have your controls set to "OFF" until all of the salt has dissolved. Only pour salt into the body of the pool- never pour the salt into the skimmer . Also, if you spread the salt out as you go across the shallow end, it will help make it easier to dissolve

This is because it can be hard to calculate the exact size of your pool when there are slopes to the bottom and sides or other unique shapes and features. If too much salt is added and the levels get too high, you'll have to drain some of the water and dilute the pool with fresh water in order to balance out the levels.

So instead, add most of what you calculated for salt instead, just in case there was a margin of error in your pool size measurements. Let the salt dissolve and then retest your salt level before adding the last of your salt.