Never having to add salt to pool?

[EvilZ]

I've had my salt system for about 8 years now. I add a fair amount of water due to evaporation (San Diego area) and have attempted to reduce the water hardness by draining appro 50% of the pool water and refilling. With all that, I still have never had to add salt to my pool and the salt level is usually at approx 3400 when my salt cell is clean.
I'm perplexed by this - any thoughts?

BTW - the water is rock hard here and draining and refilling did little to reduce the hardness.

Thank in advance for any advice.

Erik

 

[pooldv]

Welcome to TFP!

Salt does not evaporate with the water, it stays in the pool. Salt only leaves the pool through splash out, overflow and draining. Test your fill water to see what the hardness is to see if draining and filling will lower the CH. Reverse osmosis filtering is also a possibility. Lots of TFP members manage very hard water up to 800-1000 ppm CH. Watch your CSI in Poolmath and keep it slightly negative to avoid scaling issues.

More here
Pool School - Calcium Scaling
and here
Langelier and Calcite Saturation Indices (LSI and CSI)

 

[ping]

Welcome to TFP!

What was the SWG reporting the salt level before the 50% water change?

Evaporation will not lower the salt level and it might actually increase it a bit depending on how much salt is in the tap water. A couple other chemicals that you might use also add a small amount of salt to the water.

Do you test the salinity level or just go by the SWG reading? The SWG reading is the most important number but I do like to test my water once a month with my Taylor K-1766 test.

In our dry climate we rarely need to add salt to the pool to maintain it. In just over 5 years I've only added 3 bags of salt.