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Thread: A particularly challenging case of stuff growing...

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    A particularly challenging case of stuff growing...

    This season I have had an incredible problem with my pool. It appears to be a case of pink slime / white water mold, but you never can tell. Long story, but bear with me:

    It got to the point where - after brushing and vacuuming - in 2-3 days, a 1/2" layer of jellyfish-looking white blobs would attach themselves to the side and bottom of the pool, with a standard chlorine residual of 2 ppm or so. My local pool store said this was the worst case they had ever seen, and even sent samples off to be looked at. They put a treatment plan that included borates and shocking, but it didn't keep it from coming back. It infested my sand filter, gumming it up completely, and all of my laterals contained horrible amounts of gloppy **** that gummed everything up. We flushed and added new sand. We ensured every little nook and cranny was cleaned.

    After trying to treat it in this way, I got to wits' end -- only 3 options left, continue some sort of treatment plan, drain and refill after spraying everything down with bleach and letting it sit, or create a lovely rock garden and patio out of it. Because of heavy rains this year, draining really isn't a possibility right now so I decided on a "go-for-broke" treatment plan that I devised. It was simple - add chlorine until the pool reaches 20 ppm or so and let it clean out what it can. 6 hours after adding 100 lbs. in 20 lb. increments, the pool only had a FC reading of 1 ppm. That's right, after ONE HUNDRED POUNDS, it showed only ONE ppm. An additional one hundred pounds brought us up to the 25 ppm mark, and I held it there for 5 days (an additional 25 lbs was required). Once Cl PPM reached 3-5, the white blobs started releasing themselves from the smoother surfaces (walls, floors, etc.)

    5 days later, I have a crystal clear pool. We spent the first 2 days cleaning the skimmers and pump basket HOURLY to get the globs of **** that came loose and were gumming it up. We brush the sides 4 times daily.

    The problem? It's still growing, but not as bad as it was. It no longer grows on the walls or angular surfaces. I'm finding it growing small masses of jellyfish-looking white material attached to the skimmer gaskets, the light niche ring, and the strips where the vinyl liner attaches to the fiberglass steps. This despite a very high borate level (~100 ppm or so) and high Cl level (~20 ppm or so). And it's not in low-circulation areas - inside the skimmers, it's growing where water is circulating all the time.

    Test results:
    pH 7.2
    TC > 10 ppm (test strips go to 10)
    FC ~ 20 ppm
    Alk 180
    TH 350
    CYA 50

    As I understand, the standard treatment for tough pink slime / white water mold is to use high borate levels to break the biofilm apart, and high chlorine levels to kill the bacteria. I would think my current levels would preclude the growth.

    At this point, the pool is closed to swimmers.

    My next steps are to try a specific algaecide marketed by a company for the "pink" algae, and/or use a high dose of algaecide, but before that I wanted to reach out here for any suggestions.

    Any suggestions?
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Mod Squad Bama Rambler's Avatar
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    Re: A particularly challenging case of stuff growing...

    Welcome to TFP.

    First and foremost you need a good test kit. The key to getting rid of the slime is the proper amount of chlorine.

    If you added 100 lbs of "shock". most likely Dichlor or cal-hypo then you've either added 185 ppm of CYA or your CH by 165. And you've either added 201 or 235 ppm FC. What was the chlorine you added?
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: A particularly challenging case of stuff growing...

    Welcome to TFP, and yes, you do have a challenge ahead! The good news is that you found the right place to fix it!

    As Bama said, we need to know exactly what you added 100 lbs of. On the label, what is the active ingredient listed? The next step will depend on that, but you will need to read up on The SLAM Process. It sounds like it is going to take some serious work but I am confident you will be able to work through this and destroy the algae.

    Two important things: Look at a good test kit, I use the TF-100 myself (see the link in my signature). Strips aren't accurate enough to SLAM properly. Second: Ignore the algaecides for now. You should be able to fix this by properly SLAMing your pool.
    JD - 28' Round Above Ground Pool, 17,000 Gallons. Dual speed Jacuzzi pump with cartridge filter. Dual speed 1 HP pump, Hayward S210T sand filter
    Pool School - PoolMath - HIGHLY Recommended Test Kits

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    Re: A particularly challenging case of stuff growing...

    I have a long history of not trusting test kits of various types and size, so I take samples to the pool store and cross-compare with my Aqua-chek silver strips *and* my old DPD kit. All three have reported that FC has been > 20 for over 5 days, yet the small white blobs still grow. I can also confirm that 6 hours after adding 100 lbs. of 47% cal-hypo, that the FC only read between 1-2 consistently using 2 different strips *and* my DPD kit.

    After dumping the pre-diluted cal-hypo in the pool, it *instantly* oxidized stuff in the water in a pretty vigorous reaction.

    I know what you're thinking -- "That you only have a level of 20-30 is IMPOSSIBLE!" Yeah, I thought that too. In total, I've added 200 lbs. of cal-hypo and 25 lbs. of dichlor to the pool since last Sunday, and since Tuesday morning (3 1/2 days ago), the FC has come down from what looked like 30(ish) to 20.

    During this outbreak, adding 15-20 lbs. of shock to the pool resulted in no FC reading at all within a few hours.

    As for SLAM, can you help me understand why it's different than me holding the pool at > 20 FC since Sunday?

    I am getting a new test kit (whether K-2006 or TF-100) but from what I see, they max at 10 FC so it would be a while before I could do a detailed OCLT...

    Thanks in advance!
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Re: A particularly challenging case of stuff growing...

    PS: The water has been crystal clear for about 2 days now... it's just the little white blobs that I find in the morning when I look in these places...
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Mod Squad Bama Rambler's Avatar
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    Re: A particularly challenging case of stuff growing...

    Order the TF-100 and get the XL option and you can trust that. I suggest you order the SpeedStir also.

    25 lbs of Dichlor would have raised your CYA by 50 ppm itself so it almost a certainty that you have more than 50 ppm in your pool.

    Unlike most places that you visit, it's not hard at all for us to believe that you've put that much chlorine into your water and still have low to none FC in your pool.

    You need to perform the SLAM process correctly and to completion. In order to do that you are going to have to acurately know what the CYA is and you're going to have to have a FAS-DPD chlorine test. You'll also need lots of reagents for the test kit. You have to add and test as often as every hour to begin with. I guarantee you that if you follow the SLAM process you'll get your pool clear and if you'll abide by the recommendations here you'll keep it that way.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: A particularly challenging case of stuff growing...

    Thanks. TF-100 ordered.

    That said, I just want to point out that my pool is crystal clear and has been for several days now... it's just that those little white blobs keep growing around the skimmer's gasket surfaces...
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Mod Squad Bama Rambler's Avatar
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    Re: A particularly challenging case of stuff growing...

    What do the strips say your chlorine is now?
    Do they measure FC or TC?
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    techguy's Avatar
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    Re: A particularly challenging case of stuff growing...

    If your FC is 20 and your CYA is over 200, you effectively have NO CHLORINE in the pool. It takes 39FC to get to a shock level with a 100CYA and it sounds like you are above 100CYA.

    At this point, when you add chlorine, it is all binding with your CYA and your white junk is having a party and multiplying like mad.

    Strips are not accurate. CYA testing for level over 100 are not accurate. Pool stores are not known for being accurate or truthful. We use an accurate test kit, like the Tf-100 or K2006, to make accurate decisions.
    -- Guy --
    10K gallons in 21' Round 52 inch wall Aqualeader AG, Hayward Power Flow LX 1.5 HP pump motor, Hayward Perflex EC50AC DE filter w/Cellulose, Wide mouth skimmer, 2013 new Diver Dan (craigslist) to replace the faded old Hayward AquaBug. TF-100

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    Re: A particularly challenging case of stuff growing...

    Quote Originally Posted by flasherz
    I am getting a new test kit (whether K-2006 or TF-100) but from what I see, they max at 10 FC so it would be a while before I could do a detailed OCLT...
    I don't know where you saw that, the FAS-DPD test accurately tests pretty much up to infinity if you use enough powder. You will be able to measure just about any level you need to an accuracy as precise as 0.2 ppm if needed.

    Trust me, we definitely believe you lost chlorine that fast. Algae and mold will consume chlorine almost as fast as you can put it in. I am glad your water is clear, but if you are still finding white blobs then the water is still contaminated and just waiting for your FC to drop too low. Once you get your test kit and accurate results you will be able to put a good game plan in to action and stop the blobs once and for all!

    And just an aside, the words "test strips" and "pool store test" don't belong in the same sentence as "accurate." This has been verified time and time again...
    JD - 28' Round Above Ground Pool, 17,000 Gallons. Dual speed Jacuzzi pump with cartridge filter. Dual speed 1 HP pump, Hayward S210T sand filter
    Pool School - PoolMath - HIGHLY Recommended Test Kits

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    Re: A particularly challenging case of stuff growing...

    This is a specialty pool store that does not use strip-based test kits, but I will wait for the TF-100 to arrive to validate it myself.
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Re: A particularly challenging case of stuff growing...

    The two different kinds of test strips cover both TC and FC. At TC levels over 10 they don't show green anymore and turn a rather nasty shade of yellow that consumes the green. The FC is slightly darker than the "20" pad on both strips.

    They're the Aqua-Chek Silver strips.
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    techguy's Avatar
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    Re: A particularly challenging case of stuff growing...

    The DPD test is limited to 5FC, the FAS-DPD test is effective up to 50FC

    This single test is the major difference between the ones sold at Leslie's (and other retail stores) and what we collectively use to accurately measure our pools. In my normal maintenance of a clear pool, measure FC in 6-10PPM range. None of the kits sold at retailers can do this.
    -- Guy --
    10K gallons in 21' Round 52 inch wall Aqualeader AG, Hayward Power Flow LX 1.5 HP pump motor, Hayward Perflex EC50AC DE filter w/Cellulose, Wide mouth skimmer, 2013 new Diver Dan (craigslist) to replace the faded old Hayward AquaBug. TF-100

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    Re: A particularly challenging case of stuff growing...

    Thanks for the help so far, guys - I do appreciate it. This problem has been particularly troubling.

    The Silver Aqua-Chek strips have pads that show up to 20 FC and 10 TC, and for a few days FC has been consistently darker than 20. I managed to get the pool crystal clear and it looks great, just trying to finish it off here... More to come when I get the test kit and can give you fully accurate readings (and in the meantime, I'll keep the FC level > 20 with my test strips... USPS can't deliver fast enough
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Mod Squad Bama Rambler's Avatar
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    Re: A particularly challenging case of stuff growing...

    That's a good plan. Keep it as high as you can measure and wait for the test kit. I think you'll be surprised at the results once you have a good reliable test kit.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: A particularly challenging case of stuff growing...

    Ok... so received the TF-100, but in the meantime have been making sure we keep the Chlorine up.

    Overnight last night we shocked and maintained a FC level of 33.5 overnight, so we passed the SLAM OCLT. I stopped adding Chlorine (6% bleach) today.

    When measured tonight, 12 hours later, we are showing FC of 1.5.

    TF-100 test results:

    FC 1.5
    CC 0
    TA 290
    CH 550
    CYA 120 (tube goes to 100, I'm guessing around 120 or so)
    pH 7.2

    Borates are at a high concentration (likely 120-150 or so).

    We battled the nasty jellyblobs using borates and chlorine.

    I recognize the elevated CH is the result of using 200 lbs. of cal-hypo to oxidize whatever was in the pool.

    Should I have lost 31.5 ppm FC over the course of today with that CYA level?
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Re: A particularly challenging case of stuff growing...

    Quote Originally Posted by flasherz
    Should I have lost 31.5 ppm FC over the course of today with that CYA level?
    No. Are all the readings from the TF100? There's no chance you mistakenly did the test with 25 ml instead of 10 on the initial, or vice-versa on the after?
    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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    Re: A particularly challenging case of stuff growing...

    CYA 120? Have you diluted your sample to do the CYA test. This definitely could be contributing to your problem. See the extended test kit instructions here to determine your CYA. extended-test-kit-directions-t25081.html
    18*36*23 true "L" vinyl IG 29,000 gallons. SWG. TF-100 test kit.
    http://tftestkits.net/splash-page.html

  19. Back To Top    #19

    Re: A particularly challenging case of stuff growing...

    Quote Originally Posted by Richard320
    Quote Originally Posted by flasherz
    Should I have lost 31.5 ppm FC over the course of today with that CYA level?
    No. Are all the readings from the TF100? There's no chance you mistakenly did the test with 25 ml instead of 10 on the initial, or vice-versa on the after?
    Same test. All readings from TF100. 10 ml on all three (last night, this morning, and this evening).
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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    Re: A particularly challenging case of stuff growing...

    Quote Originally Posted by AimeeH
    CYA 120? Have you diluted your sample to do the CYA test. This definitely could be contributing to your problem. See the extended test kit instructions here to determine your CYA. extended-test-kit-directions-t25081.html
    Halved the CYA test and got somewhere between 60-65, so 120-130 is where I am on CYA.
    33,000 gal. L-shape IG/vinyl, sand filter (300 lbs), 2 1/2 HP pump

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