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Thread: Pool does not keep Chlorine in it!

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    Pool does not keep Chlorine in it!

    Hi- I am new to this website....believe me I have read for hours already! I have been a pool owner for 2 1/2 seasons so far..and things have gone wrong this year! I have the aquasmarte mineral/ chlorine system that puts a little bit of chlorine (and other things I am finding out) into my pool for about 12 hours a day. The problem I have is this- I have been running my dial at 6 all season (last 2 years at 2-3) and I can't keep chlorine in my pool. Every test strip I have comes up with nothing, so I went to Wal mart and got the upgrade test (working on getting the one you guys recommend)..and it still reads as 0. Here are my resluts: FC:0, Ph: 6.8, CYA:90, Alk:90. I know the ph is low, but what could be causing the low chlorine? I have been fighting algae (not bad, just around the steps) for about a week- shock and the chlorine goes right away! The pool looks crystal clear, so I am not sure if I need to shock more or not. The more I read on this site, the more I am thinking of getting rid of the aquasmarte...but I only have 1 good month left (michigan) and I hate to ruin the pool with a change over. Please help! I am thinking I need to get the ph up first...but then what? Keep shocking until the FC gets higher and stays there? How long might that be?
    30' round AGP, 22,000 gallons, Hayword 1.5hp pump, 250 lb sand filter

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    svenpup's Avatar
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    Re: Pool does not keep Chlorine in it!

    You have several things going on.

    First, as you said, your pH is low. If the test you are using has a minimum of 6.8 I fear it is much lower than you think. You should immediately get borax into your pool to get the pH up to 7.2.

    The reason you cant keep FC in the pool is because of the algae. You haven't shocked properly yet. Shock is a process wherein you bring the FC up to shock level based on CYA level (link to chart in my signature) and continue to bring it back up to that level as is is consumed (as often as once per hour). Check out the "how to shock" link in my signature.

    Your CYA is too high. It should be 30-50.

    We don't recommend mineral cartridge type "sanitizers" for several reasons:
    • They don't keep enough chlorine in the water[/*:m:139zb5jg]
    • They add CYA which builds up over time[/*:m:139zb5jg]
    • They add minerals (copper) that can cause green hair and stains on the pool that will be difficult or impossible to remove[/*:m:139zb5jg]


    I recommend:
    • get rid of the mineral system and start using liquid chlorine or bleach.[/*:m:139zb5jg]
    • Do a partial drain and refill to lower CYA and copper levels[/*:m:139zb5jg]
    • Do a real shock in accordance with the "How to Shock" article in Pool School. [/*:m:139zb5jg]
    • Learn how to use the pool calculator (link in my signature)[/*:m:139zb5jg]
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

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    Re: Pool does not keep Chlorine in it!

    Thank you for the quick response! I have put in 5lb of ph+ (the pool calculator said to add 7lb, but that is all I have at moment)...I am waiting to see if that helps. Do you think I can salvage the water without a drain? I removed the mineral cartridge and am just going with the tablet chlorine that goes in it. Turned it down to 2 and will wait to test for higher Ph and then hopefully start shocking? I plan to use liquid chlorine to shock....will that raise my cya? I really do not want to empty half the pool! Thanks for the response!
    30' round AGP, 22,000 gallons, Hayword 1.5hp pump, 250 lb sand filter

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    duraleigh's Avatar
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    Re: Pool does not keep Chlorine in it!

    vball,

    The most common issue on this forum is folks having a hard time managing a pool where the CYA is too high. Very few are successful at it and eventually come to realize they must partially drain and refill to have a good clean pool.

    That said, it can be done. You should immediately raise your FC to 7-10ppm and you must HOLD IT THERE for the rest of the swim season. Do so only using bleach....every other form of chlorinating will give you fits and you will likley be unsuccessful.

    Raise your pH to mid 7's using 20 mule team borax.

    Keep that FC between 7-10ppm constantly. Since your water is currently clear, you probably don't need to shock. When you do shock, you will need to raise the FC to 35ppm.

    Read Pool School and become very familiar with "ABC's of Poll Water Chemistry". You will need to manage the pool pretty carefully but it can be done.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Pool does not keep Chlorine in it!

    Thanks Duraleigh! I really appreciate any advice I can get right now. Well...I told the wife that the pool is closed for today...she was not happy! I am going to take the water level down to just below the skimmer and refill. Hopefully that will bring my cya down. Then I will post some new numbers and we'll go from there!
    30' round AGP, 22,000 gallons, Hayword 1.5hp pump, 250 lb sand filter

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    Re: Pool does not keep Chlorine in it!

    Ok...here is what I did: emptied about 5 inches out of the pool, refilled and tested again. These are the new numbers: FC:0, PH:7.0, ALk:100, CYA:70. I know the PH and the CYA are low and high respectively, so I added (per the calculator) 5 lb of baking soda (after realizing that may also raise my alkalinity!) and I then started the shock process. Put in 4 gallons of liquid chlorine and now I will wait to test again. My question is: how do I know when to stop shocking? In the "how to shock the pool" section it states: until cc is .5 or less (dent have the kit to check), or an overnight FC loss is less than 1.0 ppm (it is the middle of the day, so can I just go by another reading in an hour or so?) or if the water is clear - the water was clear before I shocked..so not sure what to do next. There was definitely algae in the pool...took the stairs out and a bunch behind it. I think I will go with testing in another hour and see what the FC looks like.
    30' round AGP, 22,000 gallons, Hayword 1.5hp pump, 250 lb sand filter

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    JasonLion's Avatar
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    Re: Pool does not keep Chlorine in it!

    Without a FAS-DPD chlorine test, you need to shock for longer than you otherwise would, to be sure you got all of the algae.

    What kind of test kit are you using to measure FC? All of the kits I know of that measure FC also measure CC.

    For now, what you want to do is to try and get the FC level up to around 28 and keep it there for a couple of days. That means testing the FC level every now and then to see how much it has come down and then adding more chlorine to raise it back up. While that is going on, you want to brush the entire pool at least once a day.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    Re: Pool does not keep Chlorine in it!

    You're right...instead of FC I should have said TC! I am using the walmart hth test kit...so how do I figure out how much 28 is on that? And when is it safe to swim? The pool does look crystal clear...so not sure what that means!
    30' round AGP, 22,000 gallons, Hayword 1.5hp pump, 250 lb sand filter

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    Re: Pool does not keep Chlorine in it!

    And I am still a little confused as to when to stop shocking....if the FC comes down than I am to bring it back up...but don't I want to come down to normal levels? When will I now when that is?
    30' round AGP, 22,000 gallons, Hayword 1.5hp pump, 250 lb sand filter

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    JasonLion's Avatar
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    Re: Pool does not keep Chlorine in it!

    On the OTO test in the WalMart HTH kit, the solution should be a dark orange/red/brown color when FC is around 28. You will only be able to get an approximate idea that way.

    You keep shocking until 24 hours after all signs of algae are gone.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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