What To Do For 7 Day Vacation

[Venams]

I've been using the tried and trusted Dichlor with Bleach on my tub and it has worked perfectly, leaving me with sparkling clean water.

I now have a bit of a dilemma. I have to dose daily additions of bleach to keep my water clear and with proper sanitizer levels.

So I've planned a week vacation for my family and I have absolutley no-one around me that I could charge with making my daily bleach doses.

So question begs, is there a way I can dose, possibly very high before I leave which would leave enough sanitizer in the tub until I return 7 days later?

[chem geek]

You can dose to a higher chlorine level and turn down the water temperature and IF you don't have an ozonator the chlorine should last the week. You can test this to see the 24-hour percentage of chlorine loss. If you get such loss down to 15%, then 10 ppm FC will become 3.2 ppm FC at the end of the week. A 20% per day loss would end up with 2.0 ppm FC. 25% loss, 1.3 ppm FC. But if you have an ozonator then the 24-hour loss can be 50% or higher so that you end up with less than 0.1 ppm FC. This is because ozone reacts with chlorine (to produce chloride and chlorate).

[Venams]

Thanks Chem Geek. My spa is equipped with Ozone.

Now what?

[chem geek]

Do you have control over how long the circulation pump runs? The ozonator should be off when the pump is off so having less circulation should have less ozone in which case you may be able to raise the FC and have the chlorine last the week. You can experiment turning down the circulation on-time and water temperature for a 24-hour period and see the percentage FC loss. If it's low enough (not more than 25%), then you can just raise the FC to 10 ppm before you leave and you should be OK. You don't need a lot of circulation when the spa is not in use and there is chlorine present.

If you don't have control over the ozone, then if it's on a lot of the time and you notice an ozone smell in the spa, then there may be enough ozone to keep the water disinfected, but that also means it's outgassing and wearing the hot tub cover and other components.

[Venams]

I have a Hot Springs GLEAM and the circ pump and ozone run continuously?

[chem geek]

If the ozonator is truly on all the time, then you could just take a chance hoping that there is sufficient ozone residual in the water and if problems develop over the week decontaminate by superchlorinating (to 50 or 100 ppm) and using Ahh-Some. Your other alternative is to add bromine tabs in a feeder, but then you'll have a bromine spa when you return unless you do a drain/refill.

[PreservedSwine]

You could enable summer mode on your GLEAM, which shuts down the circ pump for 8 hours a day. If you're just gone for a week, with the cover closed, I wouldn't be concerned about the chlorine going to zero for a couple days.

[Venams]

 

You could enable summer mode on your GLEAM, which shuts down the circ pump for 8 hours a day. If you're just gone for a week, with the cover closed, I wouldn't be concerned about the chlorine going to zero for a couple days.

 

So I'm thinking I could shock to 10ppm FC day I leave and lower temp to reduce chlorine use right? If so should I use shock higher than 10ppm for a week and what temp to lower hot tub?

[chem geek]

If that summer mode works as described, then maybe it will be OK. Going from 10 ppm FC to 1 ppm FC over 7 days is a 28% per day loss. I'd bet that the ozonator isn't worse than that if only run 8 hours per day, but I can't be sure -- it depends on the strength of the ozonator. You could go to 20 ppm FC since going to 1 ppm over 7 days would then require 35% per day loss. With the CYA in the water and the lower temperature, 20 ppm FC isn't as high as it sounds.