As shown in
this thread, the IC60 is the most economical and in your case with your larger pool it's essential for you to get this largest unit. It outputs 2 pounds of chlorine every 24 hours. Type the following into Google search:
and you will get
so 0.26 ppm FC per hour from the IC60 in your pool when it is on (at 100% ontime). With your hot climate, you'd probably want your CYA even higher at 80 ppm after you get the SWCG. As shown in
this post, the FC loss per hour at 80 ppm CYA with 4 ppm FC might be around 0.12 ppm though this varies by pool, but your SWCG should be able to keep up without a problem. In theory, you may be able to run with 0.12/0.26 = 46% ontime during the peak daylight hours, but you'll just need to adjust this until it works well for your pool so that you still have at least 4 ppm FC when the SWCG turns on at the start of a day.
The bigger concern regarding the evaporation is not just the water waste but the refill with water that the
2014 Riverside Water Quality Report shows Total Hardness at 208 ppm and since Calcium Hardness (CH) is typically 70% of Total Hardness, that would make CH at around 145 ppm so actually not so bad. As shown in
this pan evaporation list, Riverside in May through September averages 9" per month or 0.3" per day evaporation. If you have a 6' deep end and a 3' shallow end so average pool depth of 4.5', then your CH will increase by 145*((9/12)/4.5) = 24 ppm per month so over 6 months that's 145 ppm. So long as you dilute some with winter rain overflow each year, you should be OK.