I can't comment on the R/O water, I don't know anything about it.
There's another member that has
ammonia in her tap water and the prime takes care of it. If I were you, I'd probably get a gallon of water and see how many drops of prime it takes to neutralize the ammonia, then adjust that amount for your tank.
Cycling with fish works against the cycle. You need ammonia to develope the bacteria, but the ammonia will harm your fish. That's why is takes longer to cyle with fish, your removing the bacteria's food.
50% changes daily are recommended.