Running attached spa separately in the winter?

poolnoobgrandma

Gold Supporter
Sep 15, 2018
941
Seminole, FL
Pool Size
17000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite Pro (T-15)
We are using our attached gunite spa almost daily. We won't start heating the whole pool until March.
Right now, I'll keep the pool water from mixing with the spa water for at most a couple of days, then I'll run the whole system together for a while. Rinse and repeat. This way I don't have to try and balance a finicky small amount of water. I just make sure that the whole thing is balanced and that FC is on the high side of the acceptable range. Downside is that we have to pay the electric bill to raise the spa temp from under 70 to into the mid 90s every few days.

Is anyone running their attached spa as an isolated unit during the winter? If so, how is it working for you?
 
Is anyone running their attached spa as an isolated unit during the winter?
Yup, winter rains seem to be done for now so we heat (gas heater) and enjoy our spa now and then. It’s a spillover, but after the use I always transition back to the full system (slow spill into the pool). I hadn’t considered keeping that going for more than one evening use. It takes about 45 minutes to get it from around 55/60 to 95.
 
Yup, winter rains seem to be done for now so we heat (gas heater) and enjoy our spa now and then. It’s a spillover, but after the use I always transition back to the full system (slow spill into the pool). I hadn’t considered keeping that going for more than one evening use. It takes about 45 minutes to get it from around 55/60 to 95.
That's pretty much what we do, but sometimes we stretch it a day. For example, we heated the spa on Friday afternoon, and with family over all day Saturday I just turned off the pool filter and covered the spa. Saturday morning it just had to go from 80 to 94, which was pretty quick. After everyone was done on Saturday, I circulated the whole system for a while. Late this morning I switched back to spa mode and enjoyed a few hours.
I guess it's a tradeoff between $$ to heat the spa vs. hassle to keep the spa balanced (and the pool, too).
 
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I'm not sure why you can't let the pool drift in its own direction winter wise if the water temp is cold it shouldn't need much at all and just treat the spa as it's own entity like a regular hot tub. Add whatever is needed for sanitization which is pennies and not lose all the heating dollars. I understand it's not a covered spa so not sure how it would retain some of the heat. You can always use a solar blanket....
 
That's pretty much what we do, but sometimes we stretch it a day. For example, we heated the spa on Friday afternoon, and with family over all day Saturday I just turned off the pool filter and covered the spa. Saturday morning it just had to go from 80 to 94, which was pretty quick. After everyone was done on Saturday, I circulated the whole system for a while. Late this morning I switched back to spa mode and enjoyed a few hours.
I guess it's a tradeoff between $$ to heat the spa vs. hassle to keep the spa balanced (and the pool, too).
This is what we do with our new pool/spa. It is also a spillover. Soon our automation will be installed and we can do it via our phone.

Did you get a custom cover for the spa? I was thinking about doing this and would be interested in hearing where you got yours.
 
I'm not sure why you can't let the pool drift in its own direction winter wise if the water temp is cold it shouldn't need much at all and just treat the spa as it's own entity like a regular hot tub. Add whatever is needed for sanitization which is pennies and not lose all the heating dollars. I understand it's not a covered spa so not sure how it would retain some of the heat. You can always use a solar blanket....

This is what we do with our new pool/spa. It is also a spillover. Soon our automation will be installed and we can do it via our phone.

Did you get a custom cover for the spa? I was thinking about doing this and would be interested in hearing where you got yours.
We just have a solar cover for the spa. Better than nothing, but not serious insulation.
I think my issue is that maintaining the pool is so easy. Because of the volume, you can guesstimate your chemical additions a bit, and everything still turns out fine. The spa? I'm adding 1/4 cup (!!!?!) of muriatic acid, and dialing in the SWG is one percent at a time.
That's why I was asking who does this, and do they find that it's worth the effort.
 
I have a very small detached spa (200 gal) & use tablespoons of Ma & dichlor, along with a small measuring cup for bleach.
I often use google conversions to help me determine additions. My pool is closed now but it stays open from April to October & i use my spa all year round. Its really no big deal to maintain both - i have a separate “pool” setup in poolmath for the spa.
 
I've been trying to do the same and dial it in, still a work in process. I have an autocover but it still gets down to the low 70's by the next day, but better than the pool water at 53. The price of natural gas in CA is insane right now, so it makes a difference.

I've been running the SWG for 20 minutes at 25% with the pump at 1170 rpm's after I get out each night. I don't love doing that because I'm not running the heater when I do it, so I lose heat, but it seems like if I run the SWG with the cover closed it really smells like chlorine for a long time and doing it the night before seems to work out ok. I don't want to take the cover off to use the SWG while heating it cause it takes longer.

I add a few ounces of MA every couple of days because my pH quickly gets above 8.2, probably doesn't help that the pebble is only a few months old.
 
I've been trying to do the same and dial it in, still a work in process. I have an autocover but it still gets down to the low 70's by the next day, but better than the pool water at 53. The price of natural gas in CA is insane right now, so it makes a difference.

I've been running the SWG for 20 minutes at 25% with the pump at 1170 rpm's after I get out each night. I don't love doing that because I'm not running the heater when I do it, so I lose heat, but it seems like if I run the SWG with the cover closed it really smells like chlorine for a long time and doing it the night before seems to work out ok. I don't want to take the cover off to use the SWG while heating it cause it takes longer.

I add a few ounces of MA every couple of days because my pH quickly gets above 8.2, probably doesn't help that the pebble is only a few months old.
We connected everything last week, to heat up the pool and spa for a party. Cold snap today, so we'll see what the weather looks like and if we want to try to keep the spa separate once it warms up a bit.
 

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I'm going to try and keep the spa separate from the pool and run it at 1% on the SWG all the time and see how well that works out. Running it at 25% for 20 minutes after I get out doesn't seem optimal because I end up cooling the spa more than I'd like.
It really doesn't work that way. If when your soak is over the FC is low from nasties in the mix then the slow rise in FC from the swcg is not going to work. You need to treat the spa either before you use it or right after with liquid chlorine and just use the swcg for maintaining.
 
It really doesn't work that way. If when your soak is over the FC is low from nasties in the mix then the slow rise in FC from the swcg is not going to work. You need to treat the spa either before you use it or right after with liquid chlorine and just use the swcg for maintaining.
So, I'm still learning here, thank you for the input! I was going to try and run it at 1% all of the time and see if that is enough. It takes 30-75 minutes to heat up depending on if it's at pool temp of 53 or not and then we're running it while we're in it for another 30-60 minutes. The SWG is made for a 40K gallon pool and the attached 7x8 spa is much, much smaller (I'm not exactly sure how many gallons it is). Even if I run it at 1% for 20 minutes while I'm in it, I can smell that tell it is doing something. If I run it for only 20 min at 25% with the cover on while it's heating up or turned off, the chlorination smell is overwhelming, I just need to find the right %.

I'm going to go test the water today and see what it's at. I just remixed the spa/pool water yesterday and the chlorine was at 2 before I got in. I fully expect it to be 0 in the spa since I only ran it for 20 minutes at 1% and then got out. I'll use liquid chlorine to get it balanced and then keep experimenting but I'm pretty sure I can find a sweet spot to use the SWG on the spa unless even running it a 1% while heating and using is too much.
 
What you smell when opening is the out gassing that couldn't escape. Once the cover is open for some 20 minutes you will have lowered the CC if it was due to the fact it was closed. The smell of chlorine is the cause in effect of the chlorine sanitizing. Once there's no more sanitizing work for it the chlorine smell should be almost non existent.
 
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I'm going to try and keep the spa separate from the pool and run it at 1% on the SWG all the time and see how well that works out. Running it at 25% for 20 minutes after I get out doesn't seem optimal because I end up cooling the spa more than I'd like.
Why couldn't you run the spa at 25%, but keep the heater going?
 
I have a similar scenario and have been floating my chlorine level down all winter here in Georgia and the pool and spa are at about 5 ppm. I ran it up right before winter to about 10 intentionally.

However I thought the SWG would not operate if the water temperature is below 60F so I have it turned off.

Are you isolating the spa when heated and running the SWG? Seems easier to just add liquid chlorine but this is my first winter.

We have our pool open but have not used we run the filter pump just as though it’s summer and balance the chemicals. We run the spillway to keep both combined every few days.

We have a solar cover on the spa but it doesn’t do much I don’t think but keep the leaves out.
 
I have a similar scenario and have been floating my chlorine level down all winter here in Georgia and the pool and spa are at about 5 ppm. I ran it up right before winter to about 10 intentionally.

However I thought the SWG would not operate if the water temperature is below 60F so I have it turned off.

Are you isolating the spa when heated and running the SWG? Seems easier to just add liquid chlorine but this is my first winter.

We have our pool open but have not used we run the filter pump just as though it’s summer and balance the chemicals. We run the spillway to keep both combined every few days.

We have a solar cover on the spa but it doesn’t do much I don’t think but keep the leaves out.
Yes, spa runs on spa mode when I run the SWG. Pool can run on it's own or mix with the spa depending on if I have the valve open. You're probably right about the liquid chlorine but I'm just sick of dealing with it. If I can find a way to get it on autopilot with the SWG I would like to but if I have to dump in chlorine, no big deal. New pool so I'm experimenting.

I do the same thing as you, every couple of days I mix the pool and spa water and then have to reheat the spa from 55. If I use the spa daily and separate the water, I only have to heat from about 72-75, so it does help.
 
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