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Thread: Couple questions regarding chemical levels. Still learning...

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    Join Date
    May 2014
    redding, ca

    Couple questions regarding chemical levels. Still learning...

    Based off my other two threads, I replaced about 1/2 my water and got CYA down to 35-40. Before I found this site I had purchased some dichlor Bioguard shock from pool store, after they repeatedly told me the shock contained no CYA...I called Bioguard to confirm this and was told the indeed bioguard smart shock contains CYA (supposedly 3.6ppm CYA for every 10ppm Cl). Strike 1 pool store.....

    Before I went to return bioguard shock to pool store I tested my water myself.

    CYA 35-40, FC 8, CC 0, TA 110, CH 215, Ph 7.4.

    For sh** and giggles I had the pool store run there test again about 1.5 hours later.

    CYA 42, FC 5.1, TC 4.7, TA 93, Adjusted TA 80, CH 226, ph 7.5

    They wanted me to increase my adjusted TA to the 125-150 range. What exactly is adjusted TA compared to regular TA first of all? Everything I have read for a fiberglass pool, a TA in the range of 70-120 is optimal. Is adjusted TA something to worry about, or am I fine with my tested TA in the 90-110 range? I suspect adjusted TA is used to sell more chemicals. But wanted to get the skinny.

    They then wanted me to add another 2 lbs of smart shock to the pool.....something about chlorine lock...which from what I've gathered is a bunch of B.S. ****, my FC level was at 4.7 (well within the range taking into account the CYA/Cl chart and I've always tested 0 for CC even while slamming. I just got done SLAMMING, and passed the OCLT test 1.5 days ago with flying colors (0 ppm loss, clear water). I've been maintaining cl between 3-7 ever since.

    I didn't purchased anything from the pool store. But I wanted to confirm that my current chem levels are doing fine, and as long as my cl stays within the 3-7 range based on my 40ish CYA I'm good.

    Thanks for the help everyone, I'm new at this and still trying to figure things out. Getting a pretty good education over the last week, no doubt!
    13,600 fiberglass pool

  2. Back To Top    #2

    Join Date
    Oct 2013
    Chapin, SC

    Re: Couple questions regarding chemical levels. Still learning...

    You're learning quick! It took me a year after buying my house with a pool to learn about cya and how it screws up your pool if too high. The previous owner used nothing but Trichlor tabs and dichlor shock. After I got my K-2006 testkit and learned how to do a dilution cya test I found my cya was over 340 instead of the 40 Leslies had been telling me for over a year and 3 major algae blooms.
    Pool size: 24000gal inground Vinyl-Taylor k-2006 and k-1766 test kits and-speed stir
    Intermatic P1353ME digital timer w/freeze sensor
    CircuPool Si-45 SWCG System
    Polaris 280 vacuum/Polaris PB4-60 boost pump
    Pentair IntelliFlo VS 3hp Pump--Pentair sand filter

  3. Back To Top    #3

    Join Date
    Apr 2014
    Southern California

    Re: Couple questions regarding chemical levels. Still learning...

    Confirmed. A pool store tried to sell me some $30 Arm and Hammer basically bio guard balance pack whatever to increase my adjusted alkalinity however it was not necessary. I've never heard of this chlorine lock perhaps someone else can chime in?
    Last edited by PharmerAnthony; 05-13-2014 at 03:24 PM. Reason: Typo
    ~22,000 gallon inground plaster pool, 1 skimmer, 3 return jets
    Irregular pool sized approximately 19' x 40' 9' deep, Color Splash 3G pool light
    Pentair Clean & Clear Plus cartridge filter (part# 160301)
    1 HP Pentair Pump Model WFE-24 single speed
    Light Blue Pool Cover BBB Method

  4. Back To Top    #4
    Richard320's Avatar
    Join Date
    Jan 2010
    San Dimas, CA (LA County)

    Re: Couple questions regarding chemical levels. Still learning...

    Heydeman, your numbers are fine. How does the water look? That's the big test. Nobody but us cares how perfect your numbers are - people are impressed when they see a crystal clear sparkling pool that doesn't smell funny or burn their eyes or dry their skin.

    PharmerAnthony - "Chlorine Lock" is a pool store euphemism for "overloaded with CYA." In brief, the CYA level is so high that to get enough FC in the pool to kill the algae requires powdered chlorine by the bucketfull. The problem is that if the first bucket doesn't kill the algae (it probably won't), you've raised the CYA even more, so next trip they sell you two buckets, and the time after that three, and then they whip out the dreaded "High TDS, you need to drain" answer.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Tucson, AZ

    Re: Couple questions regarding chemical levels. Still learning...

    chlorine lock is a buzz word that they seem to use when they have no idea why the pool wont clear ... usually because your CYA is too high. But, based on their test results, I have no idea how they would come to that conclusion because that indicates things are fine.
    Jason, TFP Moderator
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  6. Back To Top    #6
    Isaac-1's Avatar
    Join Date
    May 2010
    SW Louisiana

    Re: Couple questions regarding chemical levels. Still learning...

    To answer your question about adjusted TA, I am really not sure, but think it is some combination of TA and acid demand, and I really don't care. TA is the last thing you should worry about with a pool and target numbers are really just ballpark one size fits all estimates to minimize pH drift, the problem is that target number makes certain assumptions about things like the pH of your fill water, pH of wind blown dust. etc, that are not always true for everyone.


    p.s. note this comes from someone with extremely acidic fill water, mine averages around 6.6-6.8 some nearby munipical wells are as low as 5.8
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
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