Pool Salt and Hot Tub Salt

How a Salt Water Pool Works

A salt water pool is still a chlorine pool. The difference is where the chlorine comes from. A salt chlorine generator passes pool water through a cell that converts dissolved salt into chlorine. That chlorine sanitizes the water, then turns back into salt over time.

Because the salt recycles, you are not adding it every day. You add it at opening, after heavy rain or backwashing, and whenever a test shows the level is below the target your system manufacturer sets.

Start With a Salt Test

Never add salt without testing first. Too little salt and the generator cannot make enough chlorine. Too much and many systems will show a warning or shut down. Use test strips, a digital meter or your control panel reading, then check your system manual for its target level. Most manuals include a chart that shows how many pounds of salt to add for your pool volume and current reading.

Which Pool Salt Should You Buy?

For most pools, a 40 lb bag is the standard size. Sunkissed Pool Salt is labeled high purity. Cargill Pool Salt is a crystalline salt. Morton Pool Salt, Sure Soft Pool Salt and Chemical Equipment Labs Swimming Pool Salt also come in 40 lb bags.

If you only need a small top-off, CrystalPure Pool Salt comes in an 8 lb bag, which is easier to measure and store than a full 40 lb bag.

Pool and Spa Salt Compared

Hot Tub Salt vs Pool Salt

Salt water hot tubs work on the same idea as salt water pools: a system turns dissolved salt into sanitizer. The big difference is volume. A spa holds a small fraction of what a pool holds, so a little salt changes the level quickly. That is why spa salt usually comes in smaller bags.

Home and Country USA Hot Tub and Spa Salt comes in 4 and 8 lb bags for measured refills. Dive Rite In Hot Tub and Spa Salt comes in 8 lb and 45 lb bags. Always follow your spa system manual for the target salt level and the right way to add salt.

How to Add Salt to a Pool

• Test the water and note the current salt level.
• Check your generator manual for the target level and the amount to add for your pool volume.
• Run the pump so water is circulating.
• Pour the salt into the shallow end or around the perimeter, away from the skimmer.
• Brush the salt toward the deep end to help it dissolve.
• Let the pump circulate the water, then test again before adding more.

Many manufacturers recommend turning the generator off while fresh salt dissolves. Follow your system manual on that point.

How Much to Order

For a new pool or a pool that was drained, you may need several 40 lb bags. For a routine top-off, one bag may be enough. The only reliable way to know is to test and use your manufacturer's chart. It is easier to order an extra bag and store it dry than to run short in the middle of opening weekend.

What to Watch Out For

• Adding without testing. Salt is easy to add and hard to remove. Removing it means draining and refilling water.
• Using the wrong salt. Use salt sold for pools or spas. Do not use ice melt, rock salt made for de-icing or softener salt with additives.
• Undissolved salt. Brush it in so it does not sit on the pool floor.
• Storage. Keep bags sealed and dry so the salt does not clump.

Buying by the Pallet

Pool service companies and community pools can order pool salt by the pallet. Pallets ship by LTL freight from Williamstown, NJ. We quote only the freight, and the per-bag price stays the same for everyone. Start on the bulk and pallet orders page. You may also want water softener salt for the house or specialty salt for the kitchen and garden.

Quick Answers

How many bags of salt do I need for my pool?

It depends on your pool volume, your current salt level and the target level for your chlorine generator. Test the water first, then use your system manufacturer's chart to work out how much to add.

Can I use water softener salt in my pool?

Stick to salt sold for pools. Some softener salts contain additives, such as rust remover or cleansing agents, that are not meant for pool water.

What should my pool salt level be?

Follow the target level set by your salt chlorine generator manufacturer. It is listed in the system manual and often on the control unit.

Can I use pool salt in my hot tub?

Check your spa system manual first. Hot tubs hold far less water, so smaller bags of spa salt make it easier to add the right amount.

How often do I add salt to my pool?

Salt is lost through splash-out, backwashing, draining and rain dilution rather than through chlorine production. Test regularly and add salt when your level drops below the target.

Not Sure Which Salt Your System Needs?

Send us your pool or spa system model on the contact page and we will help you choose. Our FAQ covers shipping and ordering.