How do I make this water heating system cheaper? (tank, tanks, chimney)

[Rogdog]

Our new (to us) house is in a cold climate. We have a large jetted tub in the master bath and two 50 gallon propane heaters in the garage. There's also an instant on hot water pump.

As I see it, though propane is cheaper than electric to heat water with, we have two heaters down there, losing heat. I think gas heaters have a higher heat loss than electric due to the chimney. There's also two standing pilots and, that pump is constantly turning hot water into warm and pushing it back into the tank for further heat loss.

The tanks are plummed in series and the pump returns the warm water to the cold side of the first tank. One heater would do the trick for us 95% of the time. The second is only needed to support the hot tub. There's only two of us unless we have visitors. We like the instant-on pump and want to keep it. The master bath is the farthest plumbing fixture from the heaters, naturally. It took a full eight minutes to blow the air out of the cold side when we de-winterized. It would take that long or more to get hot water in the morning without the pump.

Here's my thoughts please comment:

1>I'm proposing to move the pump to the second tank, therefore the water in the first tank would not circulate unless there was user demand.

2>I'm proposing to set the first tank to vacation or off, just leaving the pilot for convenience. It would be just be a wide spot in the supply pipe most of the time, unless I kicked it on in anticipation of a bubble in the tub or we had visitors.

3>I'm considering putting the instant-on pump on some sort of timer. We only need the instant on feature first thing in the morning. It would be nice if it came on just before wake up and just before bed time. The rest of the time there's no need to circulate water that I can think of.

Do you guys think we'd see any savings in propane with this strategy?