CSI in Winter

[ajw22]

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.

Which is why I suggested managing the pH using a submersible pump when the pool is not frozen.

 

[mgtfp]

Besides, I don't think the iron CAN stain the plaster unless its in suspension state, and that only happens with chlorine.

I'd be careful with that assumption. As far as I understand, ferrous iron is generally not stable in water and will eventually turn into ferric iron. Chlorine accelerates that process, but even without any chlorine, dissolved oxygen will still drive that reaction. (Edit: Just saw that onBalance already covered that).

And with sufficiently high pH, ferric iron will fall out of solution. With the high TA of your well water driving CO2 outgassing plus pH rising with falling temperatures anyway, you have all the ingredients for iron staining.

The oxidation process may slow down at lower temperatures, but I don't know how much of an impact that has.

It could also help that CO2 outgassing should stop or at least slow down once there is an ice cover on the water. For that reason it should be beneficial to keep maintaining pH with the help of a submersible pump until the water freezes as suggested by Allen.

 

[Rich D]

(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

I forgot to mention the other item (besides the robot) I purchased Primarily because of the new plaster being done so close to winter and I did not want any debris sitting on the new plaster floor over the winter so I wanted as much help as I could get keeping it clean after closing and before ice. I now have a Betta 2 solar skimmer. This thing is awesome. My in floor cleaner does a great job at cleaning below the surface, However it was not properly set up for optimal skimming, so I was already considering one of these but could not justify it as the skimmer does work most of the time. My pool has never been cleaner. This thing gets it all before it can sink. I am sure I will be using this during the regular season. At the very least it will dramatically cut down on my pump run time. Just do a bit of research if you do want to purchase one and be sure to get the extended warranty. They are not built for longevity but when they are working I would say they are worth every penny....

 

[jesse-99]

Well, in the end after closing (which involved draining and refilling), I spent 4-5 days getting the chemicals balanced the way I wanted for winter before the water froze. A real PITA since my pumps were winterized and I ended up having to use an extra drop in pump to circulate water for those days but...

Right before starting to adjust the chemicals:
pH: 7.9
TA: 330
CH: 125

After a couple days of adjustments:
pH 7.5 (new plaster, so anticipating a slight rise over winter and before opening)
TA: 110
CH: 335

So I'm happier overall, and my CSI is about where I want it (even though it's about the same CSI, give or take, it's just achieved differently). For all I know, having spent the time to do the chemical changes won't make one bit of difference over the next 4-5 months anyways with the newer plaster, but... maybe it'll help and I -feel- better having done it.

Next year my pool service company agreed to do the closing without draining and just air lock everything now that they've gone through the closing process with me and understand my entire system better. Closing a real PITA with 7 different individual bodies of water that need to be drained, 6 pumps, 2 filters, 37 in floor heads/Caretake system, an upper spa/waterslide, waterfalls, beach jets, disappearing edge, and countless other things. Each year, closing has taken 2 guys (with a bit of help from me) an entire day to get everything done, and I feel like my guys this year we really efficient and did a good job, it's just a real headache closing this pool.

 

[PoolStored]

WHEW!!! Great Job!