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

Thanks Thor and Ram for the quick reply. I'm presently using Kent RO Right to restore minerals, but since I have had such good results with SeaChem prime & stability, I think that I will switch to Equilibrium in the future.
I vacuum my Bettas gravel nightly and test ammonia daily. I do a 25% water change when I see any trace of ammonia, which is usually every third or fourth day. I make up several gallons of treated water to which I add a small amount of aquarium salt (1/4 tsp per gallon) and let it sit for a day or so before using.
So, according to what you're saying, forget about using a pH buffer and just stick with the Equilibrium?
Thanks again. So happy I found this forum.