CSI in Winter

[ajw22]

Again my whole point of the original post was, if my CSI is in SPEC/ideal ranges, does it matter that my TA and CH are sort of flipped from what is typical. Everything I read says, it DOESN'T MATTER so long as the CSI target is in range.

Yeah, it does matter.

With a TA of 300 your pH is likely to rise into the 9's before the pH/TA reaches equilibrium and stabilizes. See PH TA Relationship - Further Reading

If the water is not sufficiently saturated with calcium it will be absorbed from the plaster. 125 is not enough. You need 250-300 ppm. This can happen regardless of CSI.

CSI assumes reasonable water balance for the +0.6 to +0.3 to 0 to -0.3 to -0.6 guidelines to work. Your fill water is outside where you can rely on the CSI.

How did you close your pool in prior years?

Can you truck in water that is better balanced?

United Rentals has 21,000 gallon water tanks that you could pump your existing pool water into and then use to refill your pool.

There are other ways to do this if you are willing to spend some money to ease your worry.

Also, please turn on sharing of your PoolMath logs if we are going to be discussing your water chemistry. I still don't know what it is now.

 

[onBalance]

Jesse, as has been stated above, it is true that the CSI is the relevant and telling factor. One can have TA and CH outside the normal range and be just fine as balanced water.

However, since winter is coming and water balancing is difficult if not impossible, I would recommend, if possible prior to winterizing, to lower the high alkalinity of 300 ppm as much as possible and raising the CH at the same time. Having an alkalinity of 300 ppm can cause the pH to rise to about 8.7 over the winter. That would be too high and the water will be out of balance.

Inasmuch as you have a new plaster pool (and it isn't sufficiently cured (hydrated) for many months, I would delay winterizing as much as possible also, and try to brush the plaster finish as much as possible even after winterizing.

 

[jesse-99]

@ajw22 Well, now I'm just confused since earlier in the thread you said to "leave well enough alone" (post #2) when I shared that the pH was 7.8, TA was 300, and CH was 125 with my fill water, resulting in about -.09 CSI. Now it seems you are saying the opposite? (not arguing with you, just trying to understand the change of opinion here).

In prior years the water was drained each Fall and re-filled for closing (with the same fill water from the well) because nobody wants to just rely on air locking this pool.

Yes I could truck in water, but for roughly 34,000 gallons it cause me close to $3,000 to do that (I usually fill with trucked-in water in Spring). When I'd just be draining it in back in spring for opening. Not really the most economical thing to do.

-sigh- Now I'm confused on what to do as some have said to let it be, and now others are saying it's going to be a problem.

 

[ajw22]

@ajw22 Well, now I'm just confused since earlier in the thread you said to "leave well enough alone" (post #2) when I shared that the pH was 7.8, TA was 300, and CH was 125 with my fill water, resulting in about -.09 CSI. Now it seems you are saying the opposite? (not arguing with you, just trying to understand the change of opinion here).

Because I now understand better what your situation is and what you are doing.

In prior years the water was drained each Fall and re-filled for closing (with the same fill water from the well) because nobody wants to just rely on air locking this pool.

And did your plaster survive fine with that method?

Yes I could truck in water, but for roughly 34,000 gallons it cause me close to $3,000 to do that (I usually fill with trucked-in water in Spring). When I'd just be draining it in back in spring for opening. Not really the most economical thing to do.

-sigh- Now I'm confused on what to do as some have said to let it be, and now others are saying it's going to be a problem.

You are looking for a black or white answer. Water chemistry over a winter in a closed pool is not predictable. I can see the possible problems your well water can create but I can't say definitively if it will happen or not.

So wait, you drain for closing, put your well water in the pool for the winter, THEN drain out the well water to open the pool in the Spring, and then refill the pool with trucked in water??? There has to be a better way of managing your water park then that.

I go back to close as late as possible, put your well water in the pool for the winter if that is the best water you have, leave it be, and open as early as possible. You will have the well water in the pool for what, maybe 16 weeks? If the well water cuts 5 years off your plaster life, which I don't think it will, you saved $15,000 over trucking winter water in towards the next plaster job.

 

[Rich D]

(I usually fill with trucked-in water in Spring). When I'd just be draining it in back in spring for opening. Not really the most economical thing to do.

Could you clarify that part?. Are you still planning on draining and refilling in the spring?

Thanks, Rich..

 

[jesse-99]

Q. And did your plaster survive fine with that method?
A. Well, this is only my 3rd fall/closing with the pool (since 2020). From I can tell and "heard" the pool chemical were VERY poorly managed over the course of the first 11 years of the pool by the previous owner and pool company. (people telling me the pool company would come in, dump 5 gallons of MA, and leave) so after 11 years of what is likely improper care, the plaster was a little rough (not horrible) when I purchased it in late 2020.

-----In 2020, I didn't even know about TFP and let the pool company manage the closing in Fall, they completely drained, winterized, and filled with well water (same process they'd be using for years).... (plaster was 11 yrs old at this time) --
-----In 2021, I learned about TFP and managed chemicals myself through the Summer (staying within the Pool Math ideals), got rid of the old pool company, brought a new one in, and they also completely drained, winterized, and filled with well water (plaster was 12 years old at this time, and fairly rough, but not horrible, no cracks/problems, etc. )
---- In 2022, I had it re-plastered (chip out) because I wanted a smoother surface, and finally opened in August. Since then I've been again managing chemicals (staying within the Pool Math ideals), and am now ready for closing and need to completely drain (as mentioned -- to address some other concerns (not pool water chemical related) that really needs to be done -without- water in the pool.

So wait, you drain for closing, put your well water in the pool for the winter, THEN drain out the well water to open the pool in the Spring, and then refill the pool with trucked in water??? There has to be a better way of managing your water park then that.

Yes, this is what has been done for the last 13 years or so (only 2 previous under my ownership). Drain for closing, winterize, then fill with well water. Then in Spring, drain water, clean, light acid wash, and refill pool with trucked in water. (Note, prior owner in 11 years NEVER filled with truck-water in Spring, he always filled with well water in Spring too, but I decided to truck in water for Spring filling myself). Again, no pool company that has looked at my pool wants to close -without- draining. I've had 4 in total look at it (original pool company, current pool company, and 2 I brought it for pricing/eval).


You are looking for a black or white answer. Water chemistry over a winter in a closed pool is not predictable. I can see the possible problems your well water can create but I can't say definitively if it will happen or not.

Sorry if it seems I'm looking at it as black/white, I'm really not. I do understand there's a lot of variable here and problems that -might- occur as well as might -not- occur, this is why I created the thread and looking for feedback from people's opinions. I'm not sure anyone can say with 100% certainty "This xxxxxx will happen." in my situation, I'm just trying to get input to make the best informed decision. As you can imagine if I really *DO* need to bring my TA down from 300 at closing (even if my CSI is where it needs to be), that is going to be VERY difficult because while I can dump MA into, it usually takes at least 2 weeks of dumping in MA, bringing pH back up, dumping more MA in, bringing up pH, etc. and that's WITH running filter pumps and water features to do it -- I CANNOT do that as easily (lol) if all my pump and water features are winterized already. Hence the big question, if my CSI is okay at closing , am I going to be okay just riding it out through winter? I imagine you can see my dilemma ?

 

[jesse-99]

Could you clarify that part?. Are you still planning on draining and refilling in the spring?

Thanks, Rich..

Sorry, that wasn't very clear. Let me re-write those 2 sentences or so as such:

Yes I could truck in water (for this Fall closing), but for roughly 34,000 gallons it cause me close to $3,000 to do that (I know the cost of this only because I usually fill with trucked in water in the Spring opening) And if I'm just going to drain the water again in Spring for the opening, trucking in water -now- at appx $3,000 really isn't the most economical thing for me to do...

I hope that's a little clearer? Sorry about that! (every Spring it's drained for cleaning, since I cannot cover the pool, and I live in the middle of the woods, so things get real real messy, and its drained and lightly acid washed, etc. and re-filled for opening).

 

[ajw22]

Given that your previous plaster lasted for 11 years with all the mishandling 12 months out of the year by the prior owner I think your new plaster will do fine with 4 months of abuse from the well water. And you give it lots of love and balance the other 2/3 of the year.

If it gives you any comfort read @onBalance BiCarb Start-up guide...

A Bicarb Start-up guide for TFP members

It is an unfortunate fact that most tap water used to fill swimming pools is often soft, aggressive, and somewhat harmful to a new plaster surface. Therefore, in order to not damage a new plaster surface, the tap water needs to be “balanced” (meaning for new plaster, the CSI should be at least...

www.troublefreepool.com

Your water meets the TA + CH 400 to 500 ppm guideline to start. The question then becomes where the balance goes from there during the closing. Your pH will rise and we don't know how much. But pH rise brings your plaster towards scale with a positive CSI, not etching with a negative CSI.

I don't see how you can lower your TA with your pumps off.

I am back to fill the pool with well water, forgetaboutit, and open it as early as you can as soon as snow melts and temperatures are rising. Even if you open the pool and get the pumps running with the well water so you can check the pH and lower it as necessary. If your well water has no metals in it I would consider saving the $3K water fill and just open early and get the TA lowered and CH up before swim season begins.

 

[Rich D]

I imagine you can see my dilemma ?

Ughhh.. Replacing the water in the spring seems to be Overkill. Is there a definitive reason why it needs to be dumped, washed and cleaned?. Perhaps for this one time you could truck in water for the winter and not do the spring cleaning.

 

[ajw22]

since I cannot cover the pool, and I live in the middle of the woods, so things get real real messy,

Another piece of new information. I assumed a closed pool was a covered pool.

With an uncovered pool you can brush the walls during the winter as @onBalance suggested.

And as long as the water is not iced over you can circulate the water using a submersible pump, mix it up, and do pH tests, and lower the pH with acid. This will minimize the time the pH is rising unchecked once the pool freezes over. And then go back to pH checks anytime it thaws.

We were just discussing using a submersible pump for circulation with @Dirk at...

Best or Worse Sump Pump?

I just suggested to someone with a failing pump to grab a cheap submersible pump to keep the water moving while they await repairs. But I couldn't recommend a specific brand or model. I've been meaning to buy one myself, as a just-in-case backup, but every time I get inspired I get bogged down...

www.troublefreepool.com

and its drained and lightly acid washed, etc. and re-filled for opening).

Those "light" acid washes probably take more life from your plaster then the well water.

 

[jesse-99]

Given that your previous plaster lasted for 11 years with all the mishandling 12 months out of the year by the prior owner I think your new plaster will do fine with 4 months of abuse from the well water. And you give it lots of love and balance the other 2/3 of the year.

If it gives you any comfort read @onBalance BiCarb Start-up guide...

A Bicarb Start-up guide for TFP members

It is an unfortunate fact that most tap water used to fill swimming pools is often soft, aggressive, and somewhat harmful to a new plaster surface. Therefore, in order to not damage a new plaster surface, the tap water needs to be “balanced” (meaning for new plaster, the CSI should be at least...

www.troublefreepool.com

Your water meets the TA + CH 400 to 500 ppm guideline to start. The question then becomes where the balance goes from there during the closing. Your pH will rise and we don't know how much. But pH rise brings your plaster towards scale with a positive CSI, not etching with a negative CSI.

I don't see how you can lower your TA with your pumps off.

I am back to fill the pool with well water, forgetaboutit, and open it as early as you can as soon as snow melts and temperatures are rising. Even if you open the pool and get the pumps running with the well water so you can check the pH and lower it as necessary. If your well water has no metals in it I would consider saving the $3K water fill and just open early and get the TA lowered and CH up before swim season begins.

Well unfortunately, the well water has lots of iron in it, which is why I truck in water in Spring. If I fill with well water, eventually the iron goes from solution to suspension because of the FC, and the plaster and rocks and the beach, all stain really bad. So that means either constantly fighting with the iron and AA treatments and polyfill (not fun! -- lets not get into that discussion here, loL), or bring in iron-free water from a truck.

Yeah lowering the TA is going to be extremely difficult unless I manually run a separate dropable pump to circulate and aerate at the same time, which, I can, but ugh, talk about a PITA for weeks!!

You're right about the 11 years.. It could have gone another 2-3 years I'm sure, but I wanted the nice smooth plaster surface instead of the rough surface on my feets from poor chemical treatment and way overdone acid-washing too. I give it a TON of TLC (again, I'm overly picky about hitting the recommended/ideal Pool Math levels) throughout the rest of the year.

Really appreciate your input. I know there's a lot of variables to absorb here and no EASY answer, it's murky gray, as you eluded to earlier, not black/white.

 

[ajw22]

Well unfortunately, the well water has lots of iron in it, which is why I truck in water in Spring.

Scratch the idea of using the well water.

I would just use the well water for the winter and use a submersible pump to circulate the water to check and adjust the pH. Forget about the TA. TA is not what causes the problems. pH does. Manage the pH.

 

[Rich D]

I hope that's a little clearer? Sorry about that! (every Spring it's drained for cleaning, since I cannot cover the pool, and I live in the middle of the woods, so things get real real messy, and its drained and lightly acid washed, etc. and re-filled for opening)

Sorry, I had not seen this before posting my last post. My pool is a "Mini Mini ME" of your pool, so I can somewhat relate.
I have a infloor cleaner, waterfall, grotto, I also do not cover for the winter. I will always close 2nd week in November so most all of the leaves have fallen and I was able to get them with my regular pool maintenance. Then I open as early as possible. I am more in a field rather than woods so I imagine your debris is much worse in the spring. However perhaps you could invest some extra money to clean the pool without draining to be able to fill with truck water this fall.

 

[jesse-99]

Another piece of new information. I assumed a closed pool was a covered pool.

Yeah, can't cover it. It's just too massive. However, It freezes quickly (it's not very deep) and gets very LITTLE sun in winter. So I can brush for awhile but by late December it'll definitely be frozen. Plus there's areas even if it wasn't I couldn't brush, like the grotto, cause I'm not about to go into 32 degree water to brush the grotto walls/floor/benches in winter, lol.


Those "light" acid washes probably take more life from your plaster then the well water.

Yes, agreed that in the past the "light" acid washes were WAY overdone (I use the term "light" very loosely for the PAST openings, it was probably overdone, lol) and those acid washes also streaked the plaster too it was so bad. I'm guessing they did it because of all the heavy iron staining every year and a) didn't truck in water, and b) didn't know about AA treatments which are WAY easier on the plaster than acid washing. We will go way easier/lighter on the Spring acid washing now (new -pool company understand this) moving forward since there won't be as much need for it.

 

[jesse-99]

I would just use the well water for the winter and use a submersible pump to circulate the water to check and adjust the pH. Forget about the TA. TA is not what causes the problems. pH does. Manage the pH.

I'd be able drop MA into the pool and circulate probably up until mid-December or so, but it's definitely going to freeze over sometime around then, and usually (IIRC) it freezes at least 1-2' down over the course of the winter. We don't get much sun in winter back there at all, and can stay frozen until early April (again, IIRC) unless we get a nice week of 70 degree weather in March (which can happen, but not always).

 

[ajw22]

I'd be able drop MA into the pool and circulate probably up until mid-December or so, but it's definitely going to freeze over sometime around then, and usually (IIRC) it freezes at least 1-2' down over the course of the winter. We don't get much sun in winter back there at all, and can stay frozen until early April (again, IIRC) unless we get a nice week of 70 degree weather in March (which can happen, but not always).

That is about the 16 weeks I thought. The pool will survive fine with that.

 

[Rich D]

Well unfortunately, the well water has lots of iron in it,

Double Uggghhh... That would be the breaking point for me. That might be fine to use next year, However there is no way I would use that well water for the winter no matter what kind of super sequestering agent you use. Given all these factors I would not want to risk a Plaster surface that is still curing... Just My Humble opinion....

 

[jesse-99]

Double Uggghhh... That would be the breaking point for me. That might be fine to use next year, However there is no way I would use that well water for the winter no mater what kind of super sequestering agent you use. Given all these factors I would not want to risk a Plaster surface that is still curing... Just My Humble opinion....

Hmm. Well I've been using that well water for 2 months already with the brand new plaster (they plastered on a weekend, and the pool company couldn't get any pool water truck companies to fill on a weekend cause the municipalities are closed where they get their water from -- so I was forced to use well water RIGHT after the plaster to get water in it right away on the 88-92 degree day they did it, trust me I wasn't happy about using well water, but the pool plaster/company just shrugged and said sorry). Despite using that well water since opening this August I haven't had any really issues -- yes, there's been staining, but I've been able to lift the stains easy with an AA treatment or two. Besides, I don't think the iron CAN stain the plaster unless its in suspension state, and that only happens with chlorine. Since I won't be adding any chlorine with the drain/re-fill in early November, the iron in the water should just stay in solution which wont affect the plaster and won't stain. (from what knowledge I have of this at least??).

(my pool has so my situational complexities, I swear, lol...)

 

[Rich D]

won't be adding any chlorine with the drain/re-fill in early November,

With closing that late do you think you will still get as much debris in the pool? I have purchased a robot this year To help me keep things clean after the pool has closed and before the ice forms. I do not want any debris sitting on the new plaster over the winter because I did have some organic stains on the original plaster after the first winter. If you can use some alternative cleaning methods to keep the floor clean before the ice, then any additional debris will just end up on the ice so it will not be sitting on the plaster and potentially staining it. There are some other tools like this that might help.

https://www.amazon.com/POOL-BLASTER-Cordless-Hoseless-Battery-Powered/dp/B00IYPRLH8/ref=asc_df_B00IYPRLH8/?tag=hyprod-20&linkCode=df0&hvadid=198092864586&hvpos=&hvnetw=g&hvrand=6761951380405148815&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=1018362&hvtargid=pla-320650224676&psc=1

I had to do a partial drain just after my first plaster job so I could Build My waterfall. I ended up getting a ring at the level where it was drained to. I know you are doing a complete drain, so this will not be a issue for you. I just wanted to mention it in case you end up with a partial drain for some reason. This also highlights how susceptible the plaster is to staining even after the 28 days.

 

[onBalance]

Besides, I don't think the iron CAN stain the plaster unless its in suspension state, and that only happens with chlorine. Since I won't be adding any chlorine with the drain/re-fill in early November, the iron in the water should just stay in solution which wont affect the plaster and won't stain. (from what knowledge I have of this at least??).

That is not true. Dissolved iron in water will also likely precipitate out (oxidized) due to oxygen in water, not only with chlorine. Fortunately, iron staining doesn't always occur and sometimes the precipitated iron will simply get filtered out without staining the plaster. It cannot be predicted however.

Other than that, well water is actually good for new plaster. However, I am concerned that with the high alkalinity (as opposed to high calcium hardness), there is a possibility that the pH will rise significantly over the winter if not treated and kept balanced and will precipitate calcium scale all over as the water warms up.