Why can't you use table salt instead of pool salt in a salt water pool?

Answer 1

You can as it is the same thing The only drawback may be in the Case of iodized salt and what ever they put in table salt to make it flow easily.

I believe its the anti-caking agent that's added to table salt, also I think buying the pool salt would be more cost effective than a large bag of table salt (do they sell large bags? maybe at sams club or Costco)

The anti-caking agent may be magnesium carbonate - main constituent of the rock mineral dolomite & chemically similar to the calcium carbonate that is the primary constituent of chalk and limestone. So although it's much slower to dissolve in water, it would eventually increase the hardness. I don't know its scale-forming properties, but I think they are very low.

Answer 2

Think of your pool as a large pot you are preparing a meal. If you taste your meal and it is to salty you add fresh water or more of other unsalted ingredients to dilute. Salt pools are a common since thing. The only answer is something or someone is diluting the salt concentration in the water. Backwashing, leaks in shell needs water added back, meaning dilution. A small leak in the Plumbing system the size of a pin head running an average 8-10 hrs a day can yield around a 2'' to 3'' water loss in that time. Water chemistry unbalanced is also a factor in salt pools. And most of all remember that these salt/chlorine generators are not of GOD. They are made by man. They could be malfunctioning and need to be re-calibrated or replaced.