The SWCG causes bubbles in the water during operation. This aerates the water, and drives pH up. That, combined with your very high calcium are producing the scaling.

I can't say where the calcium came from, but it's not produced by the swcg.

There are some instructions for reducing the calcium levels here: http://www.poolforum.com/pf2/showthr...atment-Process

In the meantime you can reduce the scaling that gets produced by the swcg if you keep your pH levels a little lower. 7.2 or 7.4 maybe.