Does adding liquid chlorine to salt pool lower ppm of salt?

[mxfan]

I switched over to swg this last Summer and have been really happy with the results. Due to cold weather and cold water temps this Winter, I noticed that on my remote it says swg not working due to low temperatures. I checked my FC level and it was down to 1.5 ppm (I normally run it around 5 ppm). I had a salt level ppm of 3000 at that time and I added a gallon of liquid chlorine to raise the level since the swg wasn't able to due to the low water temp.
Once I added the liquid chlorine the FC level rose to 6 ppm but I noticed that the salt ppm was down to 2500?
Does adding liquid chlorine reduce the salt level? We have had rains where it lowers the salt level by 100 or so...but losing 500 ppm just in a couple of days has me puzzled.
Thanks in advance for any help!
...Eric

 

[chem geek]

Does adding liquid chlorine reduce the salt level?

No it doesn't, it increases the salt level. For every 10 ppm Free Chlorine (FC) added by chlorinating liquid or bleach, it increases the salt level by 8.2 ppm upon addition and an additional 8.2 ppm when the chlorine gets consumed/used so a net total of 16.5 ppm. You must have had some sort of test error or significant dilution.

 

[dmanb2b]

How are you measuring your salt level? SWGs do not do a good job of reading salt levels in cold weather and the lower the temp the lower the salt ppm reading will be.

 

[mxfan]

The salt ppm reading that I use is just what is shown on my remote. When we have had a heavy rain for a few days in the past the salt ppm would drop about 100 ppm or so. With it dropping so much I just figured maybe it was the liquid chlorine. Thanks for the responses!
...Eric

 

[chem geek]

The salt reading measured in the SWG unit is measuring conductivity and will be temperature sensitive. Colder water has lower electrical conductivity which is the primary reason that the SWG will shut off when the water gets colder. The unit may or may not be adjusting the salt reading it gives you to account for this variation of conductivity with temperature.

 

[mas985]

AquaLogic/ProLogic units all correct salt display for temperature. My unit readout doesn't vary by more than 100 ppm from 50 degrees to 100 degrees although short changes in temperature can have an effect since the temperature compensation is slow to react.

However, as the cells age, they will tend to read lower salt levels so it is a good idea to check actual salt levels at least once per year to make sure the readout is not too much below actual salt levels. I prefer the taylor drop test kits to test strips as they seem to match the unit readout more closely.

 

[woodyp]

Does adding liquid chlorine reduce the salt level?

No it doesn't, it increases the salt level. For every 10 ppm Free Chlorine (FC) added by chlorinating liquid or bleach, it increases the salt level by 8.2 ppm upon addition and an additional 8.2 ppm when the chlorine gets consumed/used so a net total of 16.5 ppm. You must have had some sort of test error or significant dilution.

Does this mean we'll all eventually end up with a saltwater pool by using bleach? Anything we need to do about it?

 

[dmanb2b]

Yes it does, but in reality you will likely not see your salt level rise much above 1500-2000 ppm. Salt is a byproduct of chlorine, whether it be liquid, dichlor, trichlor, etc

One of the reason why we advise checking your salt level prior to converting to a saltwater pool...in essence you may already be half way there