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Thread: Switched to SWG, Couple questions.

  1. Back To Top    #1

    Join Date
    May 2017
    Columbus, GA

    Switched to SWG, Couple questions.

    I've been a lurker for a while and understand the basic of water chemistry. I'm not expert by any means, but I get the big points. I have a FAS/DPD, of course; Taylor 2006, so all my test results are from that*. I just finished SLAMing my pool for open, and everything blued up and looking great. I just installed a Hayward AquaTrol, though I'm not generating right now as I'm waiting for FC levels to come down. Unfortunately I ran out of 0871 on my last day of SLAM, so my chlorine numbers are off of strips until more reagent comes in. I also have a little hot-tub, that I have been running an drop in SWG for about 3 years, again water looks great.

    Pool (7600gal):
    FC: 10+ (Strips)
    PH: 7.5
    TA: 125
    CH: 200
    CYA: 50
    Temp: 68
    CSI: -.036

    Spa (175gal):
    FC: 2 (Strips)
    PH: 8+ (6 Drops on the demand test)
    TA: 125
    CH: 250
    CYA: 60
    Temp: 100

    I know my TA a little high on both, with kids splashing and just general use the pool will come down on it's own and for the hottub fixing the PH may bring that down some. Alright, where I need some help and advice. This is the first year I've cared about CYA in my hottub/pool. Before now I was using TriChlor in pool (Frog, I know boo-hiss!), and the CYA build up over the year was why I switched in the first place. I hadn't added any CYA to the hottub until now, because I had thought with it being a covered hottub, I didn't have to worry about losing chlorine to the sun. Lately I have been reading the CYA helps longevity of the SWG cells, and the Hayward manual says it's needed between 60-80, and TFP charts say 70-80. (Okay, okay, I get it! =P ) Using the CSI math and poolcalc, I'm trying to keep my CSI between .2 & -.2, per my Hayward manual -- largely using CH to give me some wiggle room.

    Am I on the right path with CYA/CSI, that's something that's completely new to me. Second question, calculating how much Acid to put in for 6 drops on a 175gal tub. None of the charts go down that low. Also, I do plan adding Borates to get that silky smooth and PH stabilization I've been reading about.

    Anything I'm missing or that might apply to my tub/pool?

  2. Back To Top    #2

    Join Date
    Dec 2016
    Arlington, Texas

    Re: Switched to SWG, Couple questions.

    Use the taylor book. Acid additions are linear. 6 drops for 1000 gallons is 5.5 fl oz. So 5.5/1000*175=.9625 fl oz. I would hold off on borates. Actively get your TA down to 60-80(probably closer to 60) and see how your pH mellows out.

    Also, CYA in the hot tub reduces harshness of the FC, so it is a very good thing to have.
    310 gallon Tiger River Sumatran Spa, covered, standalone, fiberglass, Bleach
    11,000 gallon in-ground plaster pool, Hayward SmartFilter 550 (cartridge), CompuPool(Hayward) T-15 SWG, Hayward Super II pump
    Taylor Test Kit K-2006C, K-1766, SampleSizer, SpeedStir, Polaris P825

  3. Back To Top    #3

    Join Date
    May 2017
    Columbus, GA

    Re: Switched to SWG, Couple questions.

    How much does CSI matter to the SWG Cells, Pool, and Hottub? Lowering TA to 60, drops the CSI to -.4, lower than Hayward recommendations. To stay around -.2, it's 60/400 or 70/300 (TA/CH). Oh and I now my Spa's FC is low. I have the SWG in boost (extended cycle) catching up for the CYA addition.
    175 gallon LeisureBay Polysteel Spa, Standalone, Covered, ChlorMaker SWG
    7600 gallon ABG, Waterway 1.5HP 2 Speed Pump, Waterway Sand Filter, Hayward AquaTrol SWG, GL235 Solar Contoller w/ 6x 4x12 FAFCO Panels
    Solar Heater Build

  4. Back To Top    #4
    Mod Squad Jimrahbe's Avatar
    Join Date
    Jul 2014
    Bedford, TX

    Re: Switched to SWG, Couple questions.


    SWCG pools tend to stay at 7.8 for pH...

    Just letting your pH go up to 7.8 and leaving everything else alone, your CSI drops to -.01 which is perfect...

    What I know about Spa's would fit into the period at the end of this sentence.


    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Caldera Spa.

  5. Back To Top    #5
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    DFW, TX

    Re: Switched to SWG, Couple questions.

    Keeping CSI negative will help prevent scale in the pool and the SWG cell. -0.3 to 0 is best. But, -0.4 is ok too. +1 to Jim on letting pH stay 7.8, don't lower it until it rises to 8.0.
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

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