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Thread: White Mold

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    White Mold

    So I'm being told I have something called white mold in my pool. It looks like very fine white/light gray sand gathering in different spots on the bottom of the pool. It's so fine that it essentially dissipates when you touch it. It ranges from the shallow end to the deep end. We had it earlier in the season and didn't recongize it so we didn't do anything. For a period of time it went away. One, does anyone have a way I can determine if it really is white mold? The "diagnosis" came from the pool store so that's essentially worth nothing. Secondly, if it is in fact white mold, what do we need to do to get rid of it? Thank you very much.
    23,200 gallon in ground pool, Vinyl Liner, Salt Water, Variable Speed Pump Intelliflow 3hp/1.32SF/3.96 SFHP, Filter Pentair FNS PLus DE FNSP36, Heater Pentair Mastertemp 250, SWG Jandy APURE35PLG, TF-100 Test Kit

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    Mod Squad Bama Rambler's Avatar
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    Re: White Mold

    The best way to find out of it's anything organic is to run an OCLT. Do you have a good test kit?

    White mold is usually a gel like substance that's slimy to the touch.

    Is it slimy whan you touch it? It could just be dead algae.

    Post a set of test results and how you got them?
    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
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    Re: White Mold

    I have a the TF-100 test kit. Does that test for it?
    23,200 gallon in ground pool, Vinyl Liner, Salt Water, Variable Speed Pump Intelliflow 3hp/1.32SF/3.96 SFHP, Filter Pentair FNS PLus DE FNSP36, Heater Pentair Mastertemp 250, SWG Jandy APURE35PLG, TF-100 Test Kit

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    Re: White Mold

    I guess I don't know what OCLT is either. Please let me know. I'm a complete novice.
    23,200 gallon in ground pool, Vinyl Liner, Salt Water, Variable Speed Pump Intelliflow 3hp/1.32SF/3.96 SFHP, Filter Pentair FNS PLus DE FNSP36, Heater Pentair Mastertemp 250, SWG Jandy APURE35PLG, TF-100 Test Kit

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    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
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    pwrstrk's Avatar
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    Re: White Mold

    Over night chlorine loss test. Check your FC level when the sun is down adjust if needed and recheck. Remember the level. Check FC next morning before sun comes up and see if you lost any FC. If you lose more than 1ppm something is consuming your chlorine.


    Jeff
    24'x54" AG Morada RTR (by wilbar) 13'500 gal. Hayward Powerflo Matrix 1hp 2 speed. Hayward Perflex EC65 DE filter.

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    Re: White Mold

    Quote Originally Posted by Aspfam
    I have a the TF-100 test kit. Does that test for it?
    The test kit does not test for the presence of mold. What it tests for is the presence of combined chlorine which is an indicator of something organic in the water. Posting the typical test results let's everyone see if your water chemistry is out of whack. From there we can make good recommendations rather than guessing.

    Dust on the bottom is probably dead algae assuming your water chemistry is ok. White mold will be a slimy gel if it's clumped up. It might look like floating tissue paper in smaller quantities. I found it in two places in my pool. It was growing wrapped around the line that anchors the floating thermometer and in the filter basket. The skimmer basket was clear but the filter basket which is next in line had mold growing throughout the openings. Mold likes low chlorine levels and dark places.

    The float line just felt a little slimy since it is in the sun. The filter basket was choked with mold. It looked like white bread dough growing through the holes in the basket.

    You need to post FC, CC, PH and CYA at a minimum. Read pool school it will help.

    I know pool school and everyone here helped whip my pool into shape. In my case, the CYA level was off the chart so my chlorine levels were too low.
    16,500 gallon, 18" x 38" Grecian; IG Vinyl, Hayward DE

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    Re: White Mold

    The OCLT will tell you if something is "eating" your chlorine. It takes some time but it is the definitive test. The presence of CC at higher levels is an indication of something organic, but it's possible to have little or no CC and still have something growing in the pool.

    In my case, my water was clear, CC was low but I was fighting algae outbreaks every couple of weeks if I let the FC drop too low. Finding a filter basket full of mold was the breaking point for me. I got online, found TFP and took control of my pool. It's a work in progress but I feel better knowing what is going on.
    16,500 gallon, 18" x 38" Grecian; IG Vinyl, Hayward DE

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    Re: White Mold

    Thank you all. Now that I know what everyone is talking about I'll do the tests tonight. I'll also run the full spectrum of tests and post all the results here. Thank you very much.
    23,200 gallon in ground pool, Vinyl Liner, Salt Water, Variable Speed Pump Intelliflow 3hp/1.32SF/3.96 SFHP, Filter Pentair FNS PLus DE FNSP36, Heater Pentair Mastertemp 250, SWG Jandy APURE35PLG, TF-100 Test Kit

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    Mustard Algae

    We're still working on getting our pool numbers in line. As of last night our CYA was only at 30 and our chlorine was at 1-2. My wife has been noticing a "slime" on the sides and a white powder developing at the bottom. Similar to the way sand would accumulate in patches on the bottom. We do fill the pool with well water which I have been told is more likely to get mustard algae. Any suggestions for determining what it is and how to kill it?
    23,200 gallon in ground pool, Vinyl Liner, Salt Water, Variable Speed Pump Intelliflow 3hp/1.32SF/3.96 SFHP, Filter Pentair FNS PLus DE FNSP36, Heater Pentair Mastertemp 250, SWG Jandy APURE35PLG, TF-100 Test Kit

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    Re: Mustard Algae

    Is this the same problem you were asking if it is white mold? If so do not start a new topic, keep all of the discussion in one place so we can see what has already been covered and what you have done.
    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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    Mod Squad woodyp's Avatar
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    Re: White Mold

    Topics have been merged.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
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    Re: Mustard Algae

    Quote Originally Posted by Aspfam
    We're still working on getting our pool numbers in line. As of last night our CYA was only at 30 and our chlorine was at 1-2. My wife has been noticing a "slime" on the sides and a white powder developing at the bottom. Similar to the way sand would accumulate in patches on the bottom. We do fill the pool with well water which I have been told is more likely to get mustard algae. Any suggestions for determining what it is and how to kill it?
    At 30 CYA your chlorine is too low. Read the relationship in Pool School between CYA and chlorine. At 30 CYA your minimum FC level is 2, your target FC level is 4 and your shock level is 12. Without a good test kit and some solid numbers its hard to tell you what to do. Reread the previous responses. It's all good advice.

    It's a lot to read. I know it was for me. I read pool school and watched what the experts recommended until I understood why they gave the answers they did. It took some time but it finally started to make sense.

    I'll give you an example from my pool. I have a 16,500 gallon pool. The pool calculator tells me that 128 oz (1 gallon) of 12.5% bleach (sold as pool shock) will raise my chlorine level about 7.5 points. The label on the box said it will raise the level in my pool 8 points so the numbers match.

    If my FC was 2 (like your pool) and I wanted it to be at least 4 I would put in about half a gallon. That much will raise my FC in my pool 3.5 - 4 points for a total of about 6 points. Higher than 4 with some cushion. I don't have to really measure the bleach because half a bottle is pretty easy to eyeball. Make similar additions to get to a shock value of 12.

    This assumes I have good numbers for the starting point and I know what my chemicals do to my pool. To figure that out you need to use the pool calculator and start with good numbers.

    I'm fairly new at this so I can relate if it's a lot to learn.
    16,500 gallon, 18" x 38" Grecian; IG Vinyl, Hayward DE

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    Re: White Mold

    Makes sense to me. It now seems to be mustard algae instead of white mold. Our neighbors apparently get the same thing. Any recommendations for fighting this? I've also come to the conclusion that my SWG is not nor never has really worked correctly despite the claims of my installer(installed in May 2013). We have run it at 100% for 72 straight hours and still register 0 chlorine. I posted a no flow issue questions a few days ago but the installer has always focused on the filter when they should have taken the SWG apart to make sure it was installed correctly and that all the parts are functioning properly. That issue is what caused my water to fall apart and some of these issues to arise. Any tips on the mustard algae would be appreciated.
    23,200 gallon in ground pool, Vinyl Liner, Salt Water, Variable Speed Pump Intelliflow 3hp/1.32SF/3.96 SFHP, Filter Pentair FNS PLus DE FNSP36, Heater Pentair Mastertemp 250, SWG Jandy APURE35PLG, TF-100 Test Kit

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    Re: White Mold

    If you do indeed have algae growing, your SWG may not be able to keep up with the chlorine demand. That's not uncommon. Your SWG may be working fine.
    13'x22'x52" 8,000 gallon ProSeries Pool with Borates
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    Re: White Mold

    Fighting mustard algae is the same as fighting regular algae, except for the last steps. You SLAM normally until you pass all 3 tests, and then bring your chlorine to Mustard Algae level for 24 hours, soaking all of your toys and tools that were exposed to the mustard algae. pool-school/mustard_algae
    John
    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.

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    Re: White Mold

    Quote Originally Posted by Aspfam
    Makes sense to me. It now seems to be mustard algae instead of white mold. Our neighbors apparently get the same thing. Any recommendations for fighting this? I've also come to the conclusion that my SWG is not nor never has really worked correctly despite the claims of my installer(installed in May 2013). We have run it at 100% for 72 straight hours and still register 0 chlorine. I posted a no flow issue questions a few days ago but the installer has always focused on the filter when they should have taken the SWG apart to make sure it was installed correctly and that all the parts are functioning properly. That issue is what caused my water to fall apart and some of these issues to arise. Any tips on the mustard algae would be appreciated.
    If you have algae, the your SWG wont keep up. Once you get your algae killed you should increase your CYA to the range recommended for SWG, otherwise it will have trouble keeping up.
    Walnut Creek, CA. 18k gallon Pebble Sheen + 1.5k gallon IG spa, 1.5hp whisperflo main pump, Pentair clean and clear 420, Intellichlor IC20, Polaris 360 w/booster,Jandy lite 2 natural gas, plus solar with Heliomatic 5000 controller and 3/4 hp booster

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