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Thread: Closing a pool in mild climates

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    Closing a pool in mild climates

    Hello,

    Is there more general advice for closing a pool in more mild climates? Our pool is not heated so is not really usable from March-April to October-November. Melbourne averages 14 degrees celsius in winter but closer to 6 at night. Our pool guy advised us to add a particular algicide that lasts for 2-3 months, put the cover on and forget about it. Does that sound okay? You'd still want to keep the chlorine levels up right? Could you use chlorine tablets and just test occasionally?

    And then I'm guessing you would SLAM when you open the pool for use?
    Thanks,
    Keelie
    IG vinyl pool, 45,000 litres (11,500 gallons), Davey Silencer pump, Davey crystal clear sand filter, no heating, no SWG. Taylor K-2006.

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    Mod Squad kimkats's Avatar
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    Re: Closing a pool in mild climates

    Closing is up to you. There is no algicide that last for 2 to 3 months BUT with water temps below 60 F algae will not grow so....that could help that magic algicide LOL

    We have one senior member here that has left his pool open as in no cover for the first time this winter and he is LOVING it. He did have to scoop some leaves out once or twice but he gets to look at his pretty pool all year now!

    I only test about twice a week during our cold time. There is very little movement on my levels during this time except from the rain.

    SO you can cover it and leave it or leave it open and be able to see it.

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    JoyfulNoise's Avatar
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    Re: Closing a pool in mild climates

    Your climate sounds similar to mine here in Arizona, perhaps a few degrees cooler.

    The only algaecides that will last a "long" time are copper metal based algaecides and you really don't want to put metals in your pool water. Polyquat-60 can last a long time when its cold but that's just insurance against some unusually warm weather, it will not stop an algae outbreak. The most significant factor in closing a pool is waiting for the water temperature to be consistently below 59F and then closing the pool using TFP's recommended method. This method works best in colder climates where you are pretty much assured that the water temp will stay below 59F for many months straight.

    My pool (also without any solar heating) isn't really swimmable from mid-October until ~ mid-May if I just allow it to heat up naturally. The only problem is, my winters are not cold enough to justify closing the pool as the water temps are only below 59F for about 2-1/2 months (mid-Nov to the beginning of February). Therefore, closing is not really cost effective due to the expenses incurred during closing as well the likely green pool water that would have to be SLAM'd upon opening.

    Even though my pool is "open" during the winter, the cold water temps and low algae growth rates means that I can run my variable speed pump only about 3hrs/day AND my FC loss rate is less than 0.2ppm/day. I've only manually added bleach three times this winter and acid maybe four times. Aside from emptying the skimmer and leaf vacuum canister of debris, pool maintenance is very minimal. It would be much more of hassle to attempt to close my pool.


    Matt
    16k IG PebbleTec pool, 650gal spa, spillway and waterfall, 3HP IntelliFlo VS / 1.5HP WhisperFlo, Pentair QuadDE-100 filter, IC40 SWCG, MasterTemp 400k BTU/hr NG heater, KreepyKrauly suction-side cleaner Dolphin S300i robot, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

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    Jezza's Avatar
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    Re: Closing a pool in mild climates

    Keelie- you don't need to really close your pool in Melbourne- just maintain the correct FC/CYA ratio. This will also save you from having to buy algaecides. If you can manage that you won't have to SLAM either

    You'll find as pointed out that you FC demand will be relatively low and you just need to add some liquid chlorine a couple of times a week. It's pretty low maintenance really. Personally I'd steer clear of the tablets which will inadvertently raise your CYA.

    I wrap and cover my pool cover in winter with no one swimming but I also don't have a problem with debris blowing into the pool either.
    11 000 gallons, IG, Fibreglass, Monarch Sand Filter, Davey Typhoon C100M 1HP pump, Davey Chloromatic Mc16CTO ESR SWG, Davey Pool Wall Climba Robot, Daisy Solar Cover,
    K-2006

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    Re: Closing a pool in mild climates

    Quote Originally Posted by kimkats View Post
    Closing is up to you. There is no algicide that last for 2 to 3 months BUT with water temps below 60 F algae will not grow so....

    Kim
    regarding temperature affecting algae growth, these threads are from chem geek at http://www.troublefreepool.com/threa...and-cool-water:

    chem geek
    [IMG]file://localhost/Users/Marc_Laptop/Library/Caches/TemporaryItems/msoclip/0/clip_image002.png[/IMG]

    Re: Algae and cool water
    Figure 1 in this paper gives a rough idea of the maximal algae growth rates as a function of temperature. The generation time, which is how long it takes to double in population, is a little over 5 hours at 86 F but drops down to a little over 12 hours at 59 F. Algae can still grow even near freezing temps, but the growth rate is much slower (someone on The PoolForum saw algae slowly growing under their frozen-over pool!). Note that these numbers are maximums assuming ideal nutrients and sunlight. This link in Figure 3 shows growth rates are temperature-dependent in a very species-specific way.

    In practice, when the water temp gets colder, the amount of light is also reduced as more days are cloudy and the sun is lower in the sky. This one-two punch significantly slows down algae growth rates. If one also covers the pool with an opaque cover, then that cuts down sunlight even more.

    Of course, if there is any chlorine or algaecide (including borates) leftover in the pool, then that can inhibit algae growth as well.
    AND>>>
    Though the growth rate of algae slows down as water gets colder, the reaction of chlorine killing algae also slows down. So lowering the FC level too much could be risky. The main advantage of the cooler water, especially if the sun isn't on the pool due to clouds or a cover, is the lower daily FC usage. I'd keep the FC at whatever level you normally need to do to prevent algae. Though it's possible that at some cold water temperature the algae growth plummets, why take the chance that it doesn't?

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    Re: Closing a pool in mild climates

    I live in the Sacramento area in California and our winters are very mild, and not all that different from yours from what I can see from a glance.

    I don't actually "close" my pool. I shut off the auto fill, and let evaporation lower the water level so my chem's don't get as diluted from rain because I'm a cheapskate. I shut off my SWG. I check the chemicals around once a week. PH stays pretty stable, and I usually just ball park the chlorine without worrying about accuracy of reaching a certain level since no one is swimming in it. If it's in the yellow, it's fine.

    It's cold enough in the winter that algae won't grow, plus I borated my pool and I didn't have any algae during the summer. Borating is usually use for SWG systems to help with PH buffering, but has the side benefit of inhibiting algae growth.

    In spring, I bring everything back up to spec's and the "circle of life" begins again!
    SWG: CircuPool (May 2014) SI30+Plus; 3000ppm seems ideal;
    My Ideal Specs:
    FC 5; PH 7.4-7.6; TA 90; CH 350; CYA 75; = SI ~ 0.19
    14,000 gal, in ground, plaster, Cartridge filter, Borates
    TAYLOR K - 2006

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    Re: Closing a pool in mild climates

    Thanks everyone. This is the exact advice I was given:

    Winterizing:
    - add 1 litre Pool Drops from Bunnings & run pump for 1 hour
    - cover pool
    - set pump to run 3-4 hours per day

    This is the product description:
    Algaefree Pool Drops is a high strength liquid algaecide. Copper based for long life, it rapidly controls algae, slime, black spot and unwanted wall growth in swimming pools. Add directly to your pool water to keep it sparkling clear for up to 5 months.

    • High strength
    • Copper based for long life
    • Controls algae, slime, black spot and unwanted wall growth in swimming pools


    So it is copper based. From what you guys are saying as long as I keep my chlorine levels normal I don't need to add this. The cold water and chlorine will take care of it. Lovely thanks!
    IG vinyl pool, 45,000 litres (11,500 gallons), Davey Silencer pump, Davey crystal clear sand filter, no heating, no SWG. Taylor K-2006.

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    JoyfulNoise's Avatar
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    Re: Closing a pool in mild climates

    You want to stay away from metal-based algaecides (copper sulfate, typically) and bromine-based algaecides. Copper can cause difficult-to-remove staining in pools and bromine will cause excess chlorine demand. The only algaecide that TFP ever recommends using is Polyquat-60 and that is only for very specific purposes (pool closings or Ascorbic acid treatments). There is never a need to use algaecides routinely in a properly chlorinated pool.


    Matt
    16k IG PebbleTec pool, 650gal spa, spillway and waterfall, 3HP IntelliFlo VS / 1.5HP WhisperFlo, Pentair QuadDE-100 filter, IC40 SWCG, MasterTemp 400k BTU/hr NG heater, KreepyKrauly suction-side cleaner Dolphin S300i robot, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

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    Surf Hawk's Avatar
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    Re: Closing a pool in mild climates

    Thanks for the advice Joyful Noise, I'm in California and do something similar to you, where I check the values every week and add Chlorine maybe every now and then from Nov-Apr. But as a noob I was also doing the whole vacuum and brush thing every week, do you think I can stop doing that during those months when there is no use and very little chance of algae?

    My temp bottomed out at 54 about a month ago but is up to 60 now and historically will get to 70 in March. If I could not vacuum and brush until March or April I'd be one happy camper.
    22,000 gallon IG; plaster; 16x32 Rectangular, Depth 3.5-8Ft.
    Hayward Pro-Grid DE Filter - 48sqft w/ cellulose fiber & Hayward Energy Flo RS Pump - .75HP (1.85SF)
    Very old 312sqft solar system, TFT-100 Kit with Speedstir

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    Mod Squad kimkats's Avatar
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    Re: Closing a pool in mild climates

    I just run my cleaner to get any leaves out. My husband does not brush the pool at all during the cold months. It is up to you but I bet you can do without your weekly job except for getting stuff you can see out.

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    Mod Squad kimkats's Avatar
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    Re: Closing a pool in mild climates

    Quote Originally Posted by kimkats View Post
    Closing is up to you. There is no algicide that last for 2 to 3 months BUT with water temps below 50 or so algae should not grow so....that could help that magic algicide LOL

    We have one senior member here that has left his pool open as in no cover for the first time this winter and he is LOVING it. He did have to scoop some leaves out once or twice but he gets to look at his pretty pool all year now!

    I only test about twice a week during our cold time. There is very little movement on my levels during this time except from the rain.

    SO you can cover it and leave it or leave it open and be able to see it.

    Kim
    Please note I have made some changes to my post. I still have some learning to do and a kind person pointed out my errors! THANKS kind person!

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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