Leaving Spa Unattended for a Month in Winter

[johnclark]

Hi,

This question--in one form or another--has been addressed a number of times in this forum, but I'm still seeking guidance. (Which may ultimately be: repeating the question doesn't change the answer...)

Anyway: I have to leave my spa unattended for a full calendar month this winter. Where I live it's often well below freezing for days at a time. Getting someone to come and make tests and periodic adjustments to the water while I'm gone is problematic. (Read: not impossible, but inconvenient and probably expensive.)

Right before leaving, I plan to clean and refill the spa, and replace the filters. I'll set the temp to something reasonable, maybe 90 deg F or so.

Given that this pristine refill will not be used in my absence, what are the (likely) chemical/biological consequences of leaving the spa unattended for a winter month? Is algae growth likely? Does there exist an initial chemical adjustment that would minimize deleterious consequences after a month unattended? I'm OK with doing a cleanup and refill when I return; I just don't want to permanently damage any spa components.

Out of the tap, my municipal water is about pH=8, CH=70, and TA=70.

I know the safest thing to do is, "hire a service or winterize the spa." Failing that, I'm looking for the next-safest thing (if there is one).

Thanks in advance,

John

 

[pooldv]

I think it will be fine, especially since it is covered. I would balance the water as you normally do. Turn the temp down as low as the tub will let you. Raise FC level to shock level for your CYA level, Chlorine CYA Chart

Here is the process I use to maintain my tub. Been really great for 2+ years.
How do I use Chlorine in my Spa (or pool)?

 

[dirtdog]

I just left my spas for 2.5 weeks, these are the things i did and it was just fine. 2007 Hydropool Self Cleaning

-changed filter
-cleaned cover, pillows ect with chlorinated water
-filled bromine dispenser (adjustable filter housing dispenser and set to 5)
-added 2.5 tablespoons of sodium bromide ( this was overkill but didn't want to risk coming home to murky water ) This raised BR level to around 20ppm
-set temp to 95 and put the spa in sleep mode (sleep mode runs filter cycles but only heats spa to 20 below the set temperature)
-adjusted filter cycles in the morning and evening from the standard 2 hours and increased to 4 hours ( this was overkill too so my ozonater ran longer just in case )

Upon return the BR level was still at 20ppm which surprised me and the temp was around 78, still had 1/3 of the bromine taps left in the dispenser. Happy with results at the end of the day but learned that next time i can be more conservative. I drained out some water and refilled to get the ppm level down and adjusted the dispenser to 0.5, filter cycles back to 2 hours and now its good.

I think next time i will only add 1 tablespoon of sodium bromide to increase to 10ppm and adjust the ozonater cycles to run for 3 hours instead of 4.
Since you are gone for a month i would increase to at least 10ppm for the week before you go and test everyday without using the tub...track results and see where you are after the week this will give you a good gauge.

Hope this helps, if you have an ozonator make sure you have a good BR reserve and the ozonator should take care of the rest.

Edit,
Note: I did not drain and fill before I left and the water was over 1 month old....if you are going on 3 months without a water change i would recommended changing it before you go

 

[johnclark]

Hi,

Followup:

I'm the OP in this thread. I returned recently after leaving my spa unattended for a winter month.

I followed the advice provided. I'm happy to report that, upon return, my spa water looked, smelled, and measured as good as it did on the day I left.

Right before leaving, I cleaned and refilled the spa, replaced the filters, adjusted chemistry, shocked, and set the temp to 70 deg F. Measurements: pH=7.6, FC=0 (before shocking), TA=55, CH=180.

Upon return a month later, the hot tub was spotless, the water appeared unchanged (clear, odorless), and the filters looked clean. Measurements: pH=7.7, FC=0, TA=55, CH=180. I reset the temp to 100 deg F, and shocked the spa.

I am relieved that this worked out so well, and, as always, I am grateful for the good advice I receive in this forum.

It'd probably be pushing my luck, but I suspect I could have left the spa unattended even longer--perhaps 1-2 months--with few if any deleterious effects.

I'll report back if I ever actually try that.

John

 

[pooldv]

Good news! Thanks for the follow up.

 

[Tibo]

I noticed that your FC was 0 upon return. I like bromine for times when extended leaves are necessary as you can shock and then put bromine tabs in a floating dispenser. If I was gone for a month, I would just get a buddy to come down once in two weeks time to fill the dispenser up with tabs and add a cup or two of bleach. You could probably have a residual bromine level the entire time and eliminate any risk of bacterial growth with just that one visit in a month.