I had the chance over the weekend to test how much a SWCG increases the pH of the water. Once every month or so I back flush pool water through the air piping and then back into the pool. While doing this I place the SWCG into super chlorinate mode. I let the water circulate for about an hour to throughly clean out all of the spa piping.
Over the week while I was doing this, I had my pH meter out and decided to measure the pH of the pool water and also the pH of the water coming from the air piping. The water coming from the air piping was directly from the SWCG, running at 100%. The pH of the pool water was 7.45 and the pH of the water from the SWCG was 7.65.
So, in my case anyway, the SWCG increases the pH of the water in the cell by 0.2 pH units.