Hi, I have a 400 gallon hot tub in France - a Sundance, Lisbon. Everything has been purged, balanced, and is being sanitized with a SWG - disconnected the UV. No known problems. I am just looking ahead to the end of summer or possibly early winter and it will not be used for 6-9 months. Should I consider draining it or just turn off the heater and have someone I trust keep an eye on it? It does not freeze here. I tried to search for people doing similar things, but I couldn't find anything that looked definitive. It seemed pretty clear that if you can't get all the water out you are in the bug hosting mode....I'm sure others have found a "best way" to do this.
Shutdown several months and restart in spring.
- Thread starter DougJack
- Start date
- Jul 21, 2013
- 66,235
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Haven't seen a response - should I just wait? I don't need to decide until the end of July - Doug
JodieM
Silver Supporter
- Jul 18, 2013
- 566
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Truclear / Ei
Our manufacturer and installer warned us not to fully drain for winter or it would void our warranty. I put mine into economy mode and keep chlorine tabs floating through the winter and adjust TA and PH as needed when I can get to it in the snow drifts. We don’t use it in the winter.
Thanks - I notice you have a SWG and a pool. Was your wintering strategy for that setup or a hot tub?
PoolBrews
Well-known member
- Oct 16, 2019
- 593
- Pool Size
- 6750
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite Pro (T-15)
JodieM
Silver Supporter
- Jul 18, 2013
- 566
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Truclear / Ei
Doesn't help your question, but excuse for a grandkids-pic 
We run ours all winter, because the hot tub is best when it's 15F out, and the snow melts just before it hits the water
We run ours all winter, because the hot tub is best when it's 15F out, and the snow melts just before it hits the water
Great photo! We love ours in Wyoming - year round! - and the snow is great - it's just the walk through the snow that's stimulating!Doesn't help your question, but excuse for a grandkids-pic
We run ours all winter, because the hot tub is best when it's 15F out, and the snow melts just before it hits the water
View attachment 647563
That really made me think - thanks! My original experience when I first started taking over the hot-tub was that the FC collapsed rapidly and I thought that it was due to the UV and didn't dig in further. Since then I have learned a lot (thanks to this forum) and some personal exploration. I'm likely going to turn it back on in the next week or so. First I am turning off the SWG and with the UV off and no bather load am going to get a 12 hour baseline on the FC loss. Then I hope I get good enough weather to get out to turn the UV back on and see what happens with the SWG still off.
There are some numbers that I can't reconcile though, and maybe you know more about. The 24/7 pump runs at 35 gpm which means to me that there are 50k gallons/day or 126 "passes" of water through the UV tube. The unbound FC (close to 5% of FC total) supposedly is reduced by 50-90% per pass. The bound FC is roughly 20X more resistant, but there is 20X more of it, so the loss per pass on that basis is 2 * .05 * .5 * FC total (4 ppm estimate) = .2 ppm per pass. Obviously in 20 passes with no HOCL source all of the FC would be gone. Maybe the UV dose is much much lower than some estimates?