Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Algae & Low Chlorine

  1. Back To Top    #1

    Join Date
    Jun 2013
    Rockwall, TX

    Algae & Low Chlorine

    I'm SO glad to have found you guys! I bought my TF Test Kit early this week, and when it came in tonight I was like a little kid again, rushing out to play with my new chemistry set.

    So, background:

    My pool is about 4 years old now. The first two years I hired a professional pool guy who knew his stuff. My pool was perfect. Unfortunately, my Dad went on disability permanently and with that a fixed income. So, we made a deal, he would try to keep up the pool, and I would help him with the bills. Taking care of the pool can't be that bad, right?

    2 years later, we fight way too hard to keep the pool clear. One small slip-up, and it's green with algae. We check chlorine daily, and it's low. We're turning up the chlorinator, dropping tabs in the main skimmer, shocking it, etc... I feel like we're constantly "playing defense", and are never able to get in front of it. Dallas, TX is hot, of course, and we've had weird rain lately with it raining one day a week, the past 8 weeks. So, that seems to have made it even more erratic.

    I've now bought all the chemicals and materials you guys suggested, replaced the Polaris (it was about worn out), and changed out the filters in the pump. Now, to get my head wrapped around the chemistry of maintaining my pool.

    Doing my tests today, here's what I have:

    Chl: 0.5
    pH: 6.8
    CYA: 100
    CH: 270
    TA: 100
    FC: 0.5

    Any advice on steps to get back on track?

    Thanks so much all!
    16K gal, IG plaster, 250 sqft cartridge, Pentair System-3 Pump

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Silver Spring, MD

    Re: Algae & Low Chlorine

    Welcome to TFP!

    Your main issue is your CYA level. Not only is a CYA level of 100 make it exceedingly difficult to take care of the pool, it might actually be higher. The common CYA tests will report any level over 100 as 100, so your CYA level might actually be quite a bit higher.

    The best solution is to replace water to get the CYA level down below 100, and preferably down to something like 50.
    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

  3. Back To Top    #3
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Tucson, AZ

    Re: Algae & Low Chlorine

    I will respond to make it a Jason trifecta

    First step is to replace water. How much deepens on how high the CYA really is. Try that test again starting with a 50/50 mix of Pool and tap water and then double the result. The lighting is important with this test ... should be outside with back to the sun.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  4. Back To Top    #4

    Join Date
    Jun 2013
    Rockwall, TX

    Re: Algae & Low Chlorine

    Great, thank you guys!

    I suspected the CYA (I read a lot here on the site, and remember seeing something about the tablets leaving CYA which will build up over time?). Ok, let me do another 50/50 test tomorrow when it's bright outside again, and I'll post results.

    Side question, somewhat related:

    We have a pool party on the Fourth. Depending on the results of course, will I have time to get it under control by then? Or, should I just keep "doing it the hard way" until afterwards? Just curious!

    Thanks again!
    -The Other Jason
    16K gal, IG plaster, 250 sqft cartridge, Pentair System-3 Pump

  5. Back To Top    #5

    Join Date
    Jun 2012
    Howell, NJ

    Re: Algae & Low Chlorine

    Not a Jason, but my name does start with a J. First, like Jason 3 said, do the CYA test with the dilution. You will eventually have to replace at least 50% of your water. After getting the CYA down to about 50, retest pH. If it is still low, you would want to raise it to about 7.2. It is important to do this before starting the shock process, because high FC makes pH test invalid. Then you follow the shock process, as outlined in pool school (linked to in my signature.)
    7 year old ~13,500 gal 24' AGP with 1.5 hp Proline pump, 150 sqft Pleatco cartridge, filled with well water with pH of about 4.5.
    Wanda the Whale pool vacuum, home made heater, Taylor K-2006
    Cloudy Pool? 1) Order test kit. 2) Follow SLAM
    New to TFPC? Read Pool School a few times, then post questions. PoolMath will help with chemical additions.

  6. Back To Top    #6
    Richard320's Avatar
    Join Date
    Jan 2010
    San Dimas, CA (LA County)

    Re: Algae & Low Chlorine

    Well....if you work fast you could have a partial drain and refill done by the Fourth. As long as it ain't green right now.

    Or you could try maintaining it at 100 CYA, which means raising FC up to about 13 and keeping it there and then dealing with it after. To copy something I posted a while ago: It CAN be maintained with astronomical CYA, but it is not easy, nor would I recommend it. Just for starters, the pH test will always be iffy, because the FC level has to be kept so high. And the color block quick test for FC is useless. The only way to test FC is the FAS-DPD test every day.
    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!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts