I am confused by this whole thread. First off, I assume that water in Florida does not come out of the stub at 96 degrees. Maybe not 52 degrees like here but it is still a bad thermal mass that needs to be heated many degrees to get to operating temps.
Secondly, if set at 96 and ambient air temp is considerably less -- maybe not the 5 degrees we have here today but let's say its 75 -- the tub is still going to give something back and will require heating to keep it at 96.
Then, when the user demands, it needs to heat 96 degree water up 8 degrees to 104. The heater is running, then the pumps are running, then no heater is running and the tub gives back 8 degrees and the cycle repeats.
Is this common practice in the tubing community? I have been leaving mine at 102 (and have not used it in over 10 days because we all just want to kill ourselves up here due to unbelievable weather but that's another issue) and with 480 gallons, yeah, I am paying dearly at around $.125 per KwH. What is the cost of electricity in FLA? I estimate mine at around $38 per month.
Oh, by the way, a few things about Health Clubs. Their spas often suck badly. The jets are never adequate, never positioned correctly, and usually you are lucky to have one per body. By law, the tub may not be higher than 100 - 102 degrees. They are often over chlorinated for obvious reasons and are a health risk. You have to share it with people you probably don't like, they frown upon you wearing only your birthday suit, and you will find that it probably won't cost less than $50 per month. Finally, the last time I brought a cold one into my health club's hot tub, I was arrested for public consumption. Being handcuffed naked and dragged through the lobby was quite embarrassing for the other guests. Me, well, I've gotten used to it.
I did the same thing -- weighed the difference between a health club and it's services vs. what I have slowly built at home -- I have a large steam shower in my master (marvelous!), a good treadmill, free weights, my pre-owned Sundance Optima, and other trappings. In the end, I am willing to pay for the convenience of using it when I want to without driving at $.65 per mile and it's opened 24x7x365. Try setting it to 102 and keeping it there and see what happens. You need to do the math. Turn off and drain your tub for a month and see what happens before the A/C season kicks in. In the end, the total utility (that's an economics term) may be that you keep on saying that you enjoy it. As long as that's the case, it is worth cost if there is nothing wrong with it and the cost to purchase justifies it. Life is very short.
AGE