Finally seeing the ammonia go down to almost zero, getting nitrItes and nitrates. 3 1/2 weeks, feels like longer, but not too bad I guess, I didn't use any seeded media.
Each week I do a 50% water change and the water ends up at 7.2 pH, at the end of the week it is about 6.6. It hadn't occurred to me that the pH change at water change might be unhealthy to future tank residents! Of course I will do maybe twice weekly 15-20% water changes once stocked so the change won't be quite as severe. My tap is 7.8 though so there will be a jump. I think if I start using RO water now the pH will fall much too far; my tap's high GH and KH are what keeps the pH as high as 6.6.
Hmm. I liked the idea of a water softening substrate as my water is so hard, and it would be nice to not have to deal with RO for a while. Now I'm thinking the substrate changing the pH so much is more trouble than it is worth!