RO water out of the tap, what are best products for conditioning and restoring kh?

My tap water is basically RO water, that is the purification process here in the small town in Florida where I live.
I am just setting up a small tank for fishhless cycling. After adding RO Right (at the dose recommended for soft water fishes) and API proper pH 7 (double dose for my size tank), my dKH is 7, my dGH is 1 and my pH is 6.8.
Out of the tap, my GH and KH are 0-1 and my pH is 6.3.
I have been trying to slowly increase my pH to 7 before I add Dr. Tim's One & Only bacterial product to the tank, along with the ammonia chloride.
My question is this: do I have to get up to and maintain 7 pH for the tank to cycle. Should I keep adding the API proper pH 7? At a dKH of 7 I should have sufficient buffering capacity, correct? Also, why didn't my GH rise with the addition of RO Right?
I use Prime as a water conditioner. Has anyone used a natural product for maintaining a healthy pH other than something out of a bottle?
Thanks for any suggestions. I am going slow and trying to not add too many chemicals to my tank. I have a very healthy Betta who is patiently waiting in his gallon bowl.