My calcium tests at 640 and pH at 8.0 (in the afternoon). Two questions: How high is too high for calcium? How can I raise my pH without raising calcium? The only thing I can think of that would have caused the raised calcium level is that on thrusday while killing aiptasia a cap full of purple up got knocked into the tank. I don't use purpleup except for aiptasia killing however the reccomended dose for my tank is 1.5 capfuls. I have heard that purple up can even cause pH spikes, but in this case my pH is low. I got some kalkwasser recently but haven't used it yet and I don't have a reactor. Here are my parameters: ammonia: 0 nitrites: 0 nitrates: 20 pH: 8.0 phosphate: 0 calcium: 640 dkH: 12 Thanks!