Question about hot tub standard, economy, and sleep modes?

We recently bought a hot tub and have a question about what setting to put it on when we are not in it in order to conserve energy as much as possible. At this time we use the hot tub on a daily basis, or at least every other day. The standard mode keep the tub at desired temp at all times....Economy warms it to temperature a filter cycles... Sleep mode keeps it within 20 degrees of desired temp at filter cycles. There is also an standard/economy mode which I am not sure about? When we get out of the tub for the last time of the day which cycle would you put it on? Any information would be greatly appreciated. Thanks!