I have 5 gal of apple cider at about 10-11% ABV, it tastes good but has very little apple flavor. I was planning on diluting it with 5 more gal of apple juice to get it do actual apple cider alcohol levels. Then kegging and force carbing. My question is I want to use Campden tablets and K-sorbate to sterilize and preserve the cider. Do I mix the juice and cider and then treat it with the chemicals or do I treat the 5 gal of cider and then dilute with juice? Also the cider has been sitting in secondary for about 2-3 months should I move it to tertiary, if I do, do I need to top up and with what? Thanks for the any help.