All the gee-whiz stuff with aquarium controllers are great, but I think the ability to graph conditions over time with probes might be a real aide, especially on a nano aquarium. So I've been studying my pH lately - looking over the weeks for patterns and zooming in on daily shifts. What an eye-opener this has been. My pH is all over the road with a bit more variation than is healthy I fear. I need to address it, but first I am trying to understand it. Just take a look at that massive pH drop below. That happened right after the refugium light went off and the actinics went on. I think this tells me light overlap is needed. I've had it in the past and probably need to bring it back. The controller is paying off. What have you learned from your controller graphs?