Controllers and other devices that automate daily aquarium activities are great tools to ease the burdens of taking care of your reef. However, with more devices added to the mix, more points of failure are also added. Float switches can fail, timers can malfunction, and probes may go bad. All of these devices control the function of other equipment, and if they fail, your aquarium can suffer. For example, failed probes may cause an influx of CO2, which will not only affect pH, but cause your calcium reactor to keep dissolving calcium carbonate media. The reef tank’s alkalinity can skyrocket, causing severe issues with corals and other livestock. When using equipment and controllers, make sure fail safe devices and redundancies are in place.