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Thread: New Pool Owner - Maybe Algae?

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    New Pool Owner - Maybe Algae?

    Hello - I stumbled across this site this afternoon when I was trying to educate myself about pool care, and first off let me say thanks to the folks that have built this site. I feel much more empowered to solve this issue myself so I can actually enjoy my pool over labor day weekend.

    Here goes...I don't have a test kit. The previous owner of this home told me all I had to do is add salt and make sure the light stays green The water is nice and clear, but there is what appears to be some organic matter stuck in the small "pits" in in the bottom of the liner. I could get them out with my fingernail, but the pool brush and vacuum couldn't get it...I'm thinking algae. So, I went to Leslie's and got the water tested

    FAC - 0
    TAC - 0
    Salt - 2300
    CYA - 0
    TA - 80
    pH - 8

    So it would appear that it is time for me to shock...(or SLAM) this pool. I'm sure it is here somewhere, but I have a few specific questions about how to tackle this...first, some background on the pool:

    It is ~15k gallon 17x38 'eight' shaped pool with a Pentair SWG and a sand filter.

    Leslie's didn't have any chlorine or CYA, so they told me to come back tomorrow. But, before I start this process should I also buy a good test kit? I saw a couple of recommendations on this site for test kits, but if I can get the process started today/tomorrow I can keep taking samples to Leslie's or just find a test kit to buy there.

    Questions:

    -What is shock level for my pool and how much chlorine do I need to add (I've heard bleach works too? Does it matter?)
    -When should I add the CYA and how much should I add?
    -Should I go ahead and add the salt too since I'm low?
    -Should I worry about my pH being high at this point?
    -Is there anything different I should do with this being a SWG pool? Should I pump the sanitizer output up to 100%?
    -Should I buy some algaecide?

    Thanks in advance!!
    Jason

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    Mod Squad zea3's Avatar
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    Re: New Pool Owner - Maybe Algae?

    Hi, welcome to TFP! I will answer your questions within your post in red.

    Quote Originally Posted by jdebord
    Hello - I stumbled across this site this afternoon when I was trying to educate myself about pool care, and first off let me say thanks to the folks that have built this site. I feel much more empowered to solve this issue myself so I can actually enjoy my pool over labor day weekend.

    Here goes...I don't have a test kit. The previous owner of this home told me all I had to do is add salt and make sure the light stays green The water is nice and clear, but there is what appears to be some organic matter stuck in the small "pits" in in the bottom of the liner. I could get them out with my fingernail, but the pool brush and vacuum couldn't get it...I'm thinking algae. So, I went to Leslie's and got the water tested

    FAC - 0
    TAC - 0
    Salt - 2300
    CYA - 0
    TA - 80
    pH - 8

    So it would appear that it is time for me to shock...(or SLAM) this pool. I'm sure it is here somewhere, but I have a few specific questions about how to tackle this...first, some background on the pool:

    It is ~15k gallon 17x38 'eight' shaped pool with a Pentair SWG and a sand filter.

    Leslie's didn't have any chlorine or CYA, so they told me to come back tomorrow. But, before I start this process should I also buy a good test kit? I saw a couple of recommendations on this site for test kits, but if I can get the process started today/tomorrow I can keep taking samples to Leslie's or just find a test kit to buy there.

    Questions:

    -What is shock level for my pool and how much chlorine do I need to add (I've heard bleach works too? Does it matter?)Since you have 0 CYA you need to get it up to 20ppm before you begin the slam, otherwise the chlorine will burn off quickly from sun exposure. Once the CYA is 20ppm you can use the Pool calculator to determine your shock level and how much bleach you need to get there.

    -When should I add the CYA and how much should I add?Use the Pool calculator to determine how much CYA you need to reach 20 ppm in your pool.

    -Should I go ahead and add the salt too since I'm low?You can wait until the slam is complete to add salt. You shouldn't use the SWG during the slam process.

    -Should I worry about my pH being high at this point?Worry, no. Take care of first, yes. Use Muriatic acid to lower the pH to 7.2-7.5 before you begin the slam process. You can determine how much you need by using the Pool calculator.

    -Is there anything different I should do with this being a SWG pool? Should I pump the sanitizer output up to 100%?
    -Should I buy some algaecide?You shouldn't use the SWG during the slam process. They are designed to maintain low levels of chlorine over a long period of time, not to quickly raise chlorine to slam levels. You will save wear and tear on your SWG cell if you keep it off during the slam. Algaecide can help prevent an algae bloom but it won't help clean one up once it has taken hold. A pool kept at proper FC levels does not need algaecide during the swim season.

    Thanks in advance!!
    Jason
    As you may have noticed, the Pool calculator is a good tool to help you manage your pool. You will need to get a FAS/DPD test kit to complete the slam process. Most of the time they will not have one in the stores. Do not let them sell you a DPD kit, it does not test chlorine levels above 5ppm and you will need to test values higher than that to complete the slam process. You can order a Taylor K2006 or the TF100 online. The TF100 is a very good value for the price and the shipping is quick, usually just a few days.

    As for chlorine, use either liquid chlorine from the pool store or plain unscented 8.25% bleach from the grocery store. Sometime you can get CYA at Walmart, Lowes, or Home Depot.
    TFP Moderator
    Helpful links: TF Test Kits,TFP Pool School, PoolMath
    Vogue 21' round AG, Pentair 1 hp 2 speed pump, 36 sq ft DE filter, Hayward S180T 150# sand filter, Houston, Texas
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    linen's Avatar
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    Re: New Pool Owner - Maybe Algae?

    Welcome to tfp, jdebord

    zea beat me, but here are my comments:

    Quote Originally Posted by jdebord
    But, before I start this process should I also buy a good test kit?
    Yes, the process will be much more efficient with a much higher likelihood for success with a kit.

    Before we can answer most of your other questions, we need a reliable cya measurement. Pool stores get this one wrong more often the right...but it is possible that yours is very low.

    Quote Originally Posted by jdebord
    What is shock level for my pool and how much chlorine do I need to add (I've heard bleach works too? Does it matter?)
    Bleach/liquid chlorine is the best way to chlorinate for the SLAM process (and in general). If you cya is truly 0 then you SLAM level is 10 ppm.

    Quote Originally Posted by jdebord
    When should I add the CYA and how much should I add?
    Once you know what your cya is, I would add enough to raise it to 20-30 ppm during the SLAM process.

    Quote Originally Posted by jdebord
    Should I go ahead and add the salt too since I'm low?
    I wouldn't worry about the salt until you are finished with the SLAM process. My perference is to use bleach/liquid chlorine for the process. But if you decide you want the swg to "help" hold the FC level once you get to the SLAM level with bleach, then you should probably raise the salt up to ~3000 (assuming you trust the current test number). Does your swg show a salt level?

    Quote Originally Posted by jdebord
    Should I worry about my pH being high at this point?
    I would lower ph down to 7.2-7.4 before starting the SLAM process.

    Quote Originally Posted by jdebord
    Is there anything different I should do with this being a SWG pool? Should I pump the sanitizer output up to 100%?
    Again, my preference is to save your cell for normal pool maintenance and use bleach to do the SLAM process.

    Quote Originally Posted by jdebord
    Should I buy some algaecide?
    No, chlorine is all you need.

    Read/reread the SLAM process: http://www.troublefreepool.com/pool-...king_your_pool
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Re: New Pool Owner - Maybe Algae?

    Thanks!

    I tried to buy liquid chlorine from Leslie's, but all they have is "shock powder"? Should I just get some bleach from the grocery store?

    Also, the recommended CYA level for my pool is 60-90. Are you suggesting that I keep the CYA low while shocking then raise it up to that level at some point? When should I raise it? I'm also going to look for this at one of the big box stores or Wal-Mart.

    To lower my pH I'll have to add acid which will lower my TA I believe, so I'll also have to add baking soda I think. Should I do all of this before the SLAM?

    Thanks!
    Jason

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    linen's Avatar
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    Re: New Pool Owner - Maybe Algae?

    Quote Originally Posted by jdebord
    Should I just get some bleach from the grocery store?
    Yes, or bleach/liquid chlorine from a hardware store or one of the big box home improvement stores.

    Quote Originally Posted by jdebord
    Also, the recommended CYA level for my pool is 60-90.
    Not here on tfp, we recommend 70-80 ppm cya for swgs. But since you need to do the SLAM process, only bring the cya level up to 20-30 ppm until you complete the process. You still need a reliable measurement for cya. If you get one of the recommended kits suggest above you will be a good position to get your pool crystal clear.

    Quote Originally Posted by jdebord
    To lower my pH I'll have to add acid which will lower my TA I believe, so I'll also have to add baking soda I think. Should I do all of this before the SLAM?
    Don't worry about TA for now, just lower your ph down to 7.2-7.4 and start the SLAM process once you have a reliable test kit.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Re: New Pool Owner - Maybe Algae?

    TF100 has been ordered...hope it gets here in time so I can get my pool ready for Labor Day weekend

  7. Back To Top    #7

    Re: New Pool Owner - Maybe Algae?

    QQ - how long will it take for my pool to come down from shock FC level?

    Is that why we want to keep the CYA levels low until after shocking? So the extra FC burns off?

  8. Back To Top    #8
    linen's Avatar
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    Re: New Pool Owner - Maybe Algae?

    Likely it will only take a few days for the FC level to drop to normal. Good news is you can swim up to your FC SLAM level.

    The reason for the lower cya level is so that the FC levels are not so high during the SLAM process.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    Re: New Pool Owner - Maybe Algae?

    Test kit arrived and verified no cya or chlorine...so I've got the cya added and my FC reading is 12 so I'm above slam.

    Will check it in the am to see how much I drop.

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