Winterize in Southern California

[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.

[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 or this one for the K2006C 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]

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