This is really helpful. It sounds like we have similar setups. I would like to try the 24vDC pump. Someone told me it would deliver the same gpm though so I didn't bother. I think my little 12V pump is not able to keep up with demand when my 80 gal. pressure tank empties. So there is a lag and drop in pressure when the pump is working hard to fill the pressure tank. I was on the verge of just getting a regular 110 AC pump and using my DC as a backup. I would like to know how you switch between the two when you need to? Easily, that is.