I'd love 7.0 but I am not locked into any one pH only a stable pH above 6.0, I think most of my fish can handle a pH of 8.0. I think a stable pH a little above their preferred range, is much better then a shifting pH withing their preferred range. I am experimenting with ways to keep my R/O + DI water, with acceptable kH and gH readings without spending millions on chems. I think maybe I just haven't given the rock enough time, as its clearly having some effect.