Winterize in Southern California

[kirkinsd]

We have a 2 year old 24,000 gallon IG SWG pool with a cover in southern California. It rarely gets below freezing here.
My pool has been pretty much maintenance free. I add 1/2 gallon of muriatic acid twice a week to fight PH climb but that's about it for maintenance.
Last winter I covered it and ran the pump on a reduced schedule (every few days I would run it for a few hours) while still adding acid occasionally.

Can I leave it covered and stop running the pump completely? Do I need to worry about the PH rise? Will it even rise without the pump? Can I just dump a bunch of chlorine into it and stop pumping for the next 4 months?

Most of the pool closure threads here deal with colder regions so I haven’t found much on climates like mine.

Thanks

[Watermom]

Hi and welcome to the forum! Sorry you haven't gotten a reply yet. Ben has had some issues he has had to deal with the past few days and thus he hasn't yet been able to move these new posts into the general part of the forum where you'll be able to get some advice. But, he'll hopefully be able to do so soon. So, sit tight. Just wanted to let you know that your post has been read and that you aren't being ignored!

[PoolDoc]

You're adding a GALLON of muriatic acid every week to a 24,000 gallon pool? That's pretty unusual. I think you need to test your water -- not with strips -- and see if it's OK.

But, to your question: whether you can cover it and let it go all winter is pretty doubtful. If water temps stay below 65, you *probably* can (but I don't know), if you make sure it's cleaned and shocked before covering.

Maybe someone with experience closing a warm water pool can comment.

[kirkinsd]

Hi Ben,

I'll wait to hear what others in So Cal do but I value your thoughts on just shutting it down. I was hoping I could leave it off.

As for the acid - do you think that's too much acid? I add 1/2 gallon twice a week and that seems to keep the PH correct. I came to that amount after a few trips to Leslie's to have the water tested.

What would you consider a proper amount of acid on my size pool?

Thanks

[PoolDoc]

It's not so much what I consider proper as it is, wanting to understand why your pool needs so much.

A starting place would be a Taylor test kit (linked below) and some good test results.

[kirkinsd]

I tested last night with a drops kit and came up with:
FC=3+
CC=3+
PH=8.2+
Alk=140

What else would you like to see tested?

Thanks

[aylad]

I'm a little suspicious of your drop kit results--it would be highly unusual to have a CC (combined chlorine--which is chlorine that is actively fighting something in the water) of 3+ unless you're in the middle of a Baquacil conversion or have some other major problems going on. FC + CC = TC. Did you maybe mean TC of 3+ ? Also--if you're using an OTO test, you can dilute your pool water with equal parts distilled water, test from that sample, and multiply your result by 2 to get a ballpark of what your chlorine actually is.

What is your CYA level?

Janet

[mas985]

I live in Northern California under somewhat similar conditions although we get a bit colder up here. Anyway during the winter (Nov-Feb), I tend to run the pump for about 2 hours per day just to keep the leaves off the bottom (suction side cleaner) and to keep the water chlorinated. When water temps get below 50 degrees, only a couple weeks out the year, I found that algae doesn't really grow here so I can allow the pool to go "idle" for a few days or weeks without the pump running or adding chlorine plus the SWG stops working anyway so it is a win win.

Your water may not get as cold as mine so you may not be able to allow the pool to go idle but it takes some experimentation to know exactly what you can get away with. If you let the water go idle, watch it carefully and note any small changes in water color which could indicate a pending bloom.

[kirkinsd]

Janet -

I don't have a drops tester for CYA but from the strip it appears to be around 60ppm. And I did mean TC of 3+. Should I go pop for a better CYA test?

Mark - Surprisingly, I've left my pump off for the last three weeks and the test results I gave were just the other night. I'm going to go add a gallon of muriatic acid to lower the PH. I was hoping that with no pump running my PH wouldn't rise. I guess I really don't have a clue.


Kirk

[chem geek]

Your pH is too high and needs to be lowered. Part of the reason for the high pH is your high TA. A saltwater chlorine generator pool tends to rise in pH so keeping the TA lower at around 70 ppm helps as does having the Cyanuric Acid (CYA) at around 80 ppm and the FC at 4 ppm (minimum) helps to reduce the generator on-time. You can also use 50 ppm Borates, but can do that for next season if you want. You didn't tell us your CYA level nor your Calcium Hardness (CH). You should get a Taylor K-2006 kit via this Amazon link for the K2006A (http://www.amazon.com/exec/obidos/ASIN/B0002IXIIG/poolbooks) or this one for the K2006C (http://www.amazon.com/exec/obidos/ASIN/B0002IXIJ0/poolbooks) which will give a small amount to this forum (the price on Amazon for this test kit is usually excellent, however).

By the way, if you are adding 1 gallon per week to your 24,000 gallon pool, then your TA should be dropping by about 21 ppm per week. Since it is still fairly high, are you adding anything to keep the TA higher and if so you should stop doing that and let the TA drop to around 70 ppm.

[kirkinsd]

On the 16th I added 1 gallon of muriatic acid. Today I tested & got these results:
FC=2.8
PH=7.8
Alk=90
CYA=120
CH=620

So I added another 1/2 gallon of muriatic acid. My PH is down to 7.2 but do I need to deal with the hardness? My fill water only 150. I have a feeling it's time to drain half the pool. Ouch.

Do I need to deal with the CH & CYA?

Thanks,
Kirk

[chem geek]

You will need to do a partial drain/refill to lower the CYA level at some point but as to whether you do that now or wait until spring is up to you. If you don't do it now, then you should keep your FC level higher to prevent algae growth. The usual rule for an SWCG pool is an FC that is around 5% of the CYA level so around 6 ppm as your target. With the water getting cooler, algae will grow slower anyway, but then chlorine will kill the algae more slowly as well.

As for the CH, the calcite saturation index with your numbers before you added the acid is around +0.3 which isn't too bad for causing scaling in a manually-dosed plaster pool, but it would likely have you get a lot of scaling in your SWCG cell. However, as the water gets colder, your SWCG will probably shut off and you'll be manually dosing the pool over the winter. So whether you do the partial drain/refill now or later is up to you. If it were my pool, I'd probably do it now just to avoid any scaling issues if I got lax over the winter and the pH went up too much, but that's just me.

[kirkinsd]

Chem Geek -
You've confirmed what I thought I would need to do.

I'm unsure of the best way to drain. Should I drain as I add fill water or do I actually drain to just above the basket and then add fill water?

Thanks

[aylad]

Draining to just above the basket and then adding fill water will work, but it will be very slow. Assuming you're wanting to drain 1/2 the water, I would say 3 or so drains of 1/4 would work. Otherwise, I've seen reference to the "sheet method" (can't remember if it's CarlD or Poconos that has used it) where you put a sheet of plastic on top of the water and drain from under the sheet as you fill on the top--it's supposed to keep the chems in the top and bottoms from mixing.

Here's an old thread that talks about the sheet method--see ChemGeek's reply toward the bottom of the thread..http://www.poolforum.com/pf2/archive/index.php/t-6121.html

[mas985]

I've done an in-place refill before without using a sheet. The key is to introduce water at one end of the pool without too much mixing (pump off) while at the same time, remove water at the other end of the pool, preferably the deep end via a siphon. I have replaced over half the water this way and the result seemed to work without too much mixing (i.e CH dropped as predicted).