Rainsoft gold capacity settings

1 Could you tell me how to change the settings for how much gallons used between regeneration? I think it is set to high. I only use 490 gal per week on average and need to soften 2000 grains per day if I figured right.
My tank size is 8x44 with .5 cubic ft of resin. My hardness is 20 grains.
2 could I add more resin to this tank increasing it to 1cubic ft?
Any help is appreciated, thanks
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