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Thread: Numbers seem low?

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    Daisy08's Avatar
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    Numbers seem low?

    Don't know if I am over analyzing things. Pool seems and has been fine all summer. Just installed June 2015- 24,000 gallon SWG vinyl liner. I Have had to add this summer so far: stabilzer 1x at the beginning, salt 1x, PH 2x, and shock 2x. Was away for 2 days and when got home checked pool and again, all was fine. I have been testing the pool all summer with Aquacheck strips (I know, I know, not the best method of testing water). I decided to take water to Lesile's since I haven't really looked at numbers in detail. My readings basically stated that all was fine (except for hardness and phosphates; which from reading pool school, I don't need to address those issues anyway). However, it seems that even though Lesile's states all numbers are fine, from the charts I see in Pool School, it seems like I don't have enough FC and CYA. Can anyone weigh in on this based on my numbers below?

    Here are the number's Lesile's gave me:
    FAC 2
    TAC 2
    CH 130
    CYA 60
    TA 80
    PH 7.6
    Phosphates 1000
    Salt at 3000
    Generator output at 85%-90%. Its been a dry and sunny in PA the last 2 months.

    Thanks in advance for advice.
    18x36 IG Vinyl liner Pool. 25,000 gal. Installed June 2015. Salt Water Hayward Aquarite AQR9. DE filter- Hayward DE3620. Hayward Super Pump variable speed. Taylor K2006.

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    Agent99's Avatar
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    Re: Numbers seem low?

    Generally speaking, folks 'round these here parts tend to not trust the pool store's numbers. It would be sagacious to procure a TF-100 test kit so that you can keep track of your own pool. It really is the best route.

    That said, your CYA is fine and within range but your FC should be higher than 2 ppm so you may wish to crank up your SWG.

    Since things have been fine as far as you know, I would not do anything until you have your own test kit and come up with your own (more reliable) numbers. Then you can post them here and we can suggest adjustments if they are needed.

    As far as phosphates go, ignore them.
    ----Chris----
    25k IG/Spa Figure 8, 18x36, Pebble Sheen Blue Granite, Sta-Rite S8M150 Cartridge Filter, Pentair 460805 400k BTU Heater & 011018 IntelliFlo VarSpd
    Liquidator, Fafco Solar Heat, Polaris PB460 Booster Pump w/280 cleaner, Katchaleaf Cover, TF100 Test Kit, FAKE MAIN DRAIN

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    Mod Squad JVTrain's Avatar
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    Re: Numbers seem low?

    Did Leslies use drop based testing or a digital testing device? IF I trusted their results, and that's a big IF, your FC is a bit low for your CYA level. At 60 ppm CYA with a SWG, you should always have an FC of at least 3 ppm to avoid algae problems and maintain proper sanitation. Other levels are acceptable for sure.

    How long are you running your pump each day at that output?
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

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    Daisy08's Avatar
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    Re: Numbers seem low?

    Thanks for the quick responses. Yes- I do think he did a drop test not a digital one. I got a digital printout but I saw him dropping stuff into the water and then looking visually at the beaker (excuse my ignorance). We are running the pump from 9-6 everyday. To raise the FC, should I just add shock to the pool or should I do a period of super-chlorinate? or as Agent99 states, just raise level of SWG until I get to 3? I do get a little confused between shock and super-chlorinate mode. Seems like the same to me. I am a newby so there is lots to learn. Will def. order the testing kit for next year. I am in PA and will closing pool within 3-5 weeks I am sure. Will want to have the kit for opening next year. Thanks for the help...
    18x36 IG Vinyl liner Pool. 25,000 gal. Installed June 2015. Salt Water Hayward Aquarite AQR9. DE filter- Hayward DE3620. Hayward Super Pump variable speed. Taylor K2006.

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    Mod Squad JVTrain's Avatar
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    Re: Numbers seem low?

    I would do a super chlorinate cycle to see if that brings it up. You may have to increase your output to 95% or 100% during the run time or extend the run time itself to keep it there. Next year I would consider raising your CYA to 70 to see if your FC stays up higher. Is the pool covered during the day or does it get full sun? You may also benefit from splitting up your run time into two sessions of 3 hours each so that your FC level is more consistent throughout each 24 hour cycle.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

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    Agent99's Avatar
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    Re: Numbers seem low?

    The kit's reagents will last 1-2 years if stored in the house. It would be a good idea to get them now and start learning. Be sure to read up on Pool School and about closing one's pool.
    ----Chris----
    25k IG/Spa Figure 8, 18x36, Pebble Sheen Blue Granite, Sta-Rite S8M150 Cartridge Filter, Pentair 460805 400k BTU Heater & 011018 IntelliFlo VarSpd
    Liquidator, Fafco Solar Heat, Polaris PB460 Booster Pump w/280 cleaner, Katchaleaf Cover, TF100 Test Kit, FAKE MAIN DRAIN

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    Daisy08's Avatar
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    Re: Numbers seem low?

    The pool pretty much gets full sun daily. We cover the pool in the evening and take off anytime between 9am-11am. What is the theory in splitting up the run time of filter? I am intrigued.

    I have noticed that our pool will periodically get more slippery at times. We haven't scrubbed a whole lot because initially we thought that the automatic vacuum would take care of that, but it really doesn't work as effectively as doing it by hand. Works for cleaning, scrubbing no. I just wonder if the slipperiness is related to the lower FC reading? I assumed it was by nature of having a vinyl liner pool but I can def. tell that the pool gets a filmy feel to it periodically. Again scrubbing does help and also shock really does the trick How would one know if that is potential algae problem if you can't see it? Maybe I answered my own question
    18x36 IG Vinyl liner Pool. 25,000 gal. Installed June 2015. Salt Water Hayward Aquarite AQR9. DE filter- Hayward DE3620. Hayward Super Pump variable speed. Taylor K2006.

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    Mod Squad JVTrain's Avatar
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    Re: Numbers seem low?

    Think about what your SWG is doing. While it's running it's producing FC. So while it's running your FC is keeping steady and hopefully rising some. It's like very slowly dosing with liquid chlorine. Then when your SWG is off, the FC is falling. More quickly when the pool is exposed to the sunlight, very little (hopefully) at night as long as there is no algae growth going on. If you split the run time of the SWG up, your FC is more constant throughout the day. Your average FC for the whole day is the same, but it doesn't get as low or as high, it's always closer to average FC.

    I have a vinyl liner and whenever I rub my hand or foot across it firmly just below the water line, it squeaks like a freshly washed glass or plastic container. You can feel it squeak on the bottom too when I rub my hands or feet. Slippery vinyl can mean you have some algae starting. Most often it's adequate FC levels and frequent brushing/cleaner use that keeps algae away. I fully brush my pool manually only about every other week these days. I run my robot every 3 days. That and adequate chlorine levels means no algae, squeaky clean liner and pool water.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

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