Hot Tub Unattended for 10 Days - What Should I Do

[Trentpools]

Post moved here from original 3 year old thread (http://www.troublefreepool.com/threads/39273-Leaving-Spa-unattended-for-10-days)
-BoDarville, TFP Moderator

You are correct. Ozone reacts with chlorine so if you have a way to disconnect the ozonator (say by turning off the UV or CD device) then that will help make the chlorine last longer. An ozonator can be helpful in a high bather-load situation such as a residential spa used every day or two, but isn't so good when there is no bather load because it just increases chlorine demand.

Any reason not to just shut off the hot tub? This lowers the temperature to ambient and also disables the ozonator.

Would this cause problems with heater corrosion as the temperature falls, or does chlorine need additional mixing?

 

[Splash99]

I would just throw a few extra tsp. of chlorine in to bring your FC levels up a few PPM, then leave it turned on and walk away. Maybe turn your temperature down to save a little electricity. If the ozonator was going to consume the chlorine, then it was going to disappear eventually anyway on its own. On the bright side, once the FC is gone, at least you'll have the ozonator in there doing something. (That is, if ozonators actually do anything. Conflicting reports out there between worthless sales gimmick, works a little but increases chlorine usage, works a lot and decreases chlorine usage, and it's all you need! My spa came with one, I will continue to use it until failure then reconsider when I see the replacement cost. I feel like mine helps, but have no emperical evidence to support that claim. I sometimes leave mine for quite a while before checking or adding chlorine, and my water is always clear and odor free even if the FC is gone. I bring the sanitizer levels back up, and all is good.)

In my opinion, the worst thing you could do is turn the hot tub off. The circulation helps keep the bad guys at bay, even when the sanitizer is gone. Bad things tend to happen to pools and spas when the circulation is cut off, even when they initially have proper levels of sanitizer. Just sayin'!

If you left it running, and could have someone come by say after five days and throw in a tablespoon of chlorine, you would be golden!

Good luck!

 

[chem geek]

You can lower the circulation pump run time and that should lower the amount of ozonator on-time as well and will also lower the temperature if you have that set lower (and the pump heat itself will be less since it won't run as long). I would not shut it off completely. Circulation helps to distribute the disinfectant to prevent pathogens from growing. Nevertheless, you could probably just do a few hours each day, preferably spread out during the day say in a 30-minute on-time every 6 hours. Spa water turns over rather quickly so the runtime need not be for very long.

 

[Trentpools]

Thanks! As mentioned in another thread, I've been having trouble maintaining FC on a 24-hour basis let alone a multi-week basis. At this point, I'm thinking either a drain and fill (new tub, so an ahhsome treatment could be in order anyways) or see what happens and drain and fill if I come back to a swamp. Other alternatives would be convert to bromine (where ozonator is an asset), throw a Natural2 stick in there as a backup, or up my CYA a LOT.

I've been toying with the idea of a partial bromine system, which I've seen discussed before. Yes, I know there's no such thing, but can't you put in just enough sodium bromide so that you reach max 4 ppm when FULLY converted to bromine? This is quite different from having an unknown/huge bromine bank. Over a few weeks of disuse, the ozonator will hopefully maintain the bromine level. When you come back, you return to your normal chlorine schedule and eventually the bromine gets inactivated and you're back to chlorine only? Perhaps this would take longer than the refill interval.

 

[chem geek]

The ozonator will create some bromine though not that much when the bromide level is so low, BUT ozone also oxidizes bromine to bromate so will use it up. The problem is that it's hard to know how quickly it's using it up.

When bromine gets used/consumed on its own oxidizing bather waste (not from ozone) it becomes bromide so does not go away.

 

[Trentpools]

I see, so the bromine generation rate through ozonator is dependent on size of bromide bank. Sounds like my idea won't work/would be too unpredictable.