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Thread: Algae survival?

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    Algae survival?

    so i am completely stumped at this point: i had algae at the beginning of the season because of a broken pump, got this fixed and followed the algae advice in pool school, and got rid of it (or so i thought). the last few days, i have seen what HAS to be algae growing on the walls, especially around the pool light and ladder. i can send a pic later if need be. anyway, here is why i am stumped: my numbers have been perfect the last month, i have only let my FC level drop below 4 one time, and i immediately bumped it up to 5. here are my #s tested last night and then this AM:
    FC 5
    CC 0
    TC 5
    TA 80
    PH 7.5
    CYA 50-60 i know i need to get this back up, we've had a ton of rain here

    overnight, i had no FC loss. is this still algae that has hung around that i wasn't able to completely kill? is it even possible for algae to survive that long in water that has sufficient FC levels?

    any explanation would be very helpful. thanks!

    eric
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    Post a pic. Mustard algae can be resistent to normal FC levels. It requires high shock levels to attack and high normal levels to prevent from returning. It's possible you have FC "dead spots" where during the day, certain areas of the pool drop too low during the day, from uv loss and the algae possibly lurking. So if you can post a pic that would help us i.d., Usually FC holding overnight indicates it's not algae though.

    How much run time do you give your pump, and does it run at all during the day?
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    Re: Algae survival?

    that's what i thought about the FC holding overnight too, that's why i'm stumped. when i get home i'll take a pic and post it.

    i run the pump anywhere from 10-12 hours a day (usually from 9 am-8 pm) with the SWG set on 20% (sometimes 40% if it's really sunny or a lot of people swimming) and it's kept my FC very steady.
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    Well, that should prevent dead spots. Will hold judgement till I see the photo.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    Re: Algae survival?

    ok, so i need to revisit my issue. i thought i got rid of whatever this was but it is back and "better" than ever. i ran the aquabot all weekend and also shocked to MA level. my current levels are:
    FC 17
    CC 0
    TA 70
    ph 7.5
    CYA 50-60

    i haven't had overnight FC loss although i didn't test last night, but will tonight/tomorrow AM. here are some pics of my pool, there is some dirt in there from some rain last night. please, if anyone has any answers, i am all ears! thanks!

    eric


    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    Re: Algae survival?

    hmm, the pics didn't load....

    let me try this:
    http://s966.photobucket.com/albums/ae14 ... =slideshow
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    See this chart:
    http://www.troublefreepool.com/chlor...art-t2346.html

    After you complete the shock process, keep your FC at the Mustard Algae minimum for a month or so. Make sure you treat all pool toys, ladders, etc. while at shock level, and check in any trouble spots that get poor circulation.

    Not saying it's for sure Mustard, but might as well err on the side of caution.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    Re: Algae survival?

    i think the biggest reason i am totally confused by this is the lack of chlorine loss at night. also, if it was algae, wouldn't i have combined chloramines? this summer i haven't ever had more than 0.5 during any chlorine test...
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    No, not necessarily. CC doesn't always show up when algae is present.... Which does point to mustard algae, which can survive in chlorinated water and not show up distinct overnight losses.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    Re: Algae survival?

    one last question: if it's possible to have mustard algae and not experience overnight FC loss or measurable CCs, how do you know if you've gotten rid of it? thank you again for your help!
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    Quote Originally Posted by goodnterribles
    how do you know if you've gotten rid of it?
    It doesn't come back.

    I guess you don't, until you see it come back.... Just shock for a couple of days, treating all areas where it can hide and pool toys carefully (wash suits and towels in hot soapy water), then maintain the higher FC level for a few weeks. It may take a routinely higher FC level in your pool. Every pool situation is different.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    Re: Algae survival?

    ok, thanks for the advice. i'm gonna give this a shot. maintaining a FC level in the 7.5 range shouldn't be tough since my SWG can usually do that at 40%. the shock level is another story but i'll just have to keep at it. thanks again!
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    Re: Algae survival?

    I don't like maintaining such a high FC reading in a pool for so long. I use Yellow Treat Plus for a quick solution IMO
    -Kevin
    X-Pert Pool Service
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    22,000 gal / 16' x 32' / Vinyl / Hayward s244t /Pentair SuperFlo 1 hp

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    The Mustard Algae routine goes like this...shock to Normal shock level for a couple of days until no FC loss overnight. Raise up to MA level for 24 hours, making sure all pool toys, ladders, floats, ect have been exposed to the shock, brushing poor circ areas like behind ladders, light niches etc... Then maintain the higher "min" and "target" for a few weeks or so, ensuring it doesn't return. Running at the higher "min" and "target" doesn't hurt anything at all, just costs you more for bleach. The MA shock level is only for a short time and it won't hurt anything either.

    Prolonged periods of MA shock level can fade a liner, but we don't recommend that.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    JasonLion's Avatar
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    Re: Algae survival?

    Unless you know exactly what you are doing, Yellow Treat Plus is just as likely to cause problems as it is to solve them.
    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

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    Re: Algae survival?

    Quote Originally Posted by X-PertPool
    I don't like maintaining such a high FC reading in a pool for so long. I use Yellow Treat Plus for a quick solution IMO
    See this post. FC by itself means almost nothing without knowing the CYA number. FC is simply the chlorine capacity or reserve, but does not tell you the strength or activity of the chlorine. Even at the yellow/mustard algae shock level of an FC that is roughly 60% of the CYA level, this is technically equivalent in terms of chlorine strength (reaction rates) to an FC of only 1.4 ppm FC with no CYA.

    Many indoor pools, most of which don't have any CYA in the water, have higher active chlorine levels. My wife experiences this every winter season when she has to use a community center pool that is indoors with 1-2 ppm FC and no CYA compared to our own outdoor pool in the summer with 2-5 ppm FC (normally 3-4) and 30 ppm CYA. Her swimsuits degrade (elasticity gets shot) after just one winter season while in our own pool in the summer they last for many seasons. Her skin is flakier and hair frizzier after using the pool with no CYA over the winter while in our own pool even in the sun these effects are minimal. The difference is that the active chlorine (hypochlorous acid) concentration in the indoor pool with no CYA is 10-20 times higher than in our outdoor pool with CYA. Having 30 ppm FC with 50 ppm CYA is not nearly as harsh as it sounds.

    When you use Yellow Treat Plus (see here), you simply convert your pool to a bromine pool and bromine does not combine with CYA so you get "full-strength" of bromine. You simply work around the CYA, but in terms of harshness it is no different than simply raising the FC level with chlorine when there is CYA present. In fact, Yellow Treat is roughly the same as the mustard/yellow algae shock levels of chlorine. At one pound (of 88.8% sodium bromide) in 20,000 gallons, this raises the bromine level to 5.3 ppm bromine which is equivalent to 2.3 ppm chlorine with no CYA so is roughly similar to mustard/yellow algae shock level.

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

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    Re: Algae survival?

    ok, well i got my FC up to 23.5 last night. this morning it dropped down to 17.5. it could be the algae but we also had a thunderstorm in the middle of the night and i found 2 dead mice in the skimmer i am gonna keep the MA shock level for a few days, and then let it gradually drift down to the high FC target.
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    You don't want to do the MUstard Algae shock level for more than 24 hours - it could fade your liner. If you maintain normal shock for a few days with NO overnight loss, then boost to MA level for 24 hours, then let it drop to MA-Min levels, that should do the trick.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    Re: Algae survival?

    ok thanks. since i am already at MA shock level, can i let it get down to regular shock level and keep it there until no overnight FC loss? or will that not do the trick>?
    25K gallon IG vinyl liner, Intellichlor IC40 SWG, Sand Filter

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    frustratedpoolmom's Avatar
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    Re: Algae survival?

    That should do it.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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