I'm a computer programmer, not a chemist, so forgive me in advance...
I get the disassociation NaCl's sodium and chloride to make chlorine.
So, why don't I need to eventually add more salt to keep me from running out of Cl?
Well several pool "experts" have told me that the "used up cl", recombines with the sodium and the cycle repeats...
I'm guessing, the water coming out of the SWG has chlorine and "sodium something" that is a base and is why the ph constantly goes up.
I add muriatic (hydrochloric) acid to bring PH down.
I'm thinking the chloric part of the acid recombines with the sodium as it balances the ph and that's how things recycle back to NaCl.
If I'm right, in the end you're really getting your endless supply of chlorine really from the muriatic, not the salt?