Potassium Chloride

[easttn]

Im hearing about people using potassium chloride instead of sodium chloride for salt in the pool. Doing some looking around it appears to be a salt substitute and related to water softeners.

How much potassium chloride does it take to get the same ppm of salt as if you were using sodium chloride? It may say on a bag of it but I dont have one to look at.

 

[chem geek]

There is no good reason to use potassium chloride instead of sodium chloride for a pool and it's generally more expensive. It is the chloride that is used by a saltwater chlorine generator and you aren't drinking the pool water so potassium vs. sodium doesn't matter.

It takes 1.276 times the amount of potassium chloride by weight compared to sodium chloride for the same quantity of ions in the water, but from a conductivity point of view it's roughly equal weight for potassium and sodium chloride.

 

[easttn]

Ok thanks.

So if I were to put 1,000 lbs sodium chloride in pool A and 1,276 lbs potassium chloride in pool B, they would both show the exact same salt ppm on a strip or test kit?

Edit: Misread your post chemgeek. You said the chloride is what the SWG uses. Been a long day.

 

[Melt In The Sun]

Ideally yes, if salt strips were perfectly accurate. You don't need potassium chloride, but you could use it if you want. The only time it might be a good idea is if you were on a strict low sodium diet and loved to chug pool water.

 

[easttn]

It might cost you more but if the grocery store ran out of bananas then you would still be good to go.
Thanks guys.

 

[JamesW]

It partly depends on which SWG you have.

SWGs, like the AquaRite determine salinity based on the production characteristics of the cell and water temperature. For that type of SWG, it's the chloride that matters.

However, SWGs that have a separate salinity sensor, like the AutoPilot or Jandy AquaPure, detemine salinity based on conductivity, which is affected by all ions.

The AquaPure and AutoPilot can be recalibrated to match the test, if necessary.

It also depends on which salt test you're using. Test strips and the Taylor k-1766 measure chloride, whereas a meter uses conductivity.

To be safe add less than you think you will need and retest to see what the amount added accomplished.

As long as you use sodium chloride, everything should be fine. There's no benefit to using potassium chloride.

In addition to extra cost, you could potentially have other problems. For example, although the AquaPure measures salinity using conductivity, it also assess the production characteristics of the cell and compares them to the expected characteristics based on the calculated salinity.

Since the production characteristics are determined by chloride, there will be a mismatch, which could potentially cause the unit to halt production and display an error code indicating high or low current.

In that case you could probably resolve the issue by recalibrating the salt to match the measured chloride level.

For example, if you had an AquaPure and a starting salt of 200 ppm and wated the correct chloride level for 3400 ppm salt, you would add about 480 lb sodium chloride or about 615 lb potassium chloride. However, the salinity reading would be about 4300, which would cause a high salt error and possibly a low current error. Then you could recalibrate the salt to 3400 ppm.