Ok. I've played with it a bit more now, at least in the context of Water/Ice. I still don't like most of the Water spells, and later on, you get enough Ice spells that you can and probably should replace Aqua Splash with a superior Ice spell, which will do essentially the same thing except with higher damage and without any of the drawbacks. If you really need more P-Attack gems, Forward Dash is generally better at that than Aqua Splash. So the progression seems to be Ice + healing > Ice + Aqua Splash Combos > back to Ice + healing. I dunno. Maybe it's just not for me, but I significantly prefer Wind.