Spence,

The Smart-fly turbo reg has a switch option that you should use. Its a "fail safe" switch in that it makes contact (i.e., switch closed) to turn it OFF. One thing to note is that the Turbo Reg. (and other regs that have this "fail safe" cutoff) draws about 20 mA when its off, so you should unplug it from the batteries at the end of the day - or else it will drain them flat...

Bob