My ph is 8.0 or so. I see many places that neocaridina are recommended to be at 7.5 or less, but I have had no problems.
The cardinal's behavior is different. It seems a little shyer in that it likes to hang out on the rocks beneath the wood "bridge," though it does venture out plenty. It will graze on the marimo balls and the wood, but it really prefers to graze on the slate best, and it has not shown any interest in the java or taiwann moss, unlike the others. It also is not interested in blanched zucchini.