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Thread: Algae returning on liner

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    Algae returning on liner

    Hi everyone,

    I really appreciate the respect that the experienced members show the new guys.

    Here we go...
    My CC has been zero for a couple weeks, but I don't understand why I keep getting what I think is algae regrowing on my liner.

    A quick description of what I think is the algae: you can turn it into a cloud and basically clean off the liner by waving your hand around it, so it is not "attached" to the liner and a couple days after cleaning it, you can see that where it "grows" back it shows the outlines of where the pool brush was last used (you can see the streaks from where the bristles on the brush contact the liner).

    I only have two days worth of test results to show and they are almost a week apart because when I first started testing and wasn't recording the data, I didn't see ANY change in my chemicals and I was happy enough with them so I extended the time in between tests. Also, it is raining right now, so I didn't want to go test it today.

    Test results:
    6/25:
    TA-140
    pH-7.5
    FC-7.5
    CC-0 (there was no change in color when I added the solution after testing the FC with the TF kit that's all I am looking for right?)
    TC-7.5
    Calcium Hardness -110
    CYA - 50

    6/30:
    FC - 5.0
    CC - 0 (same thing, no change in color after adding the solution when the FC test was completed)
    TC - 5.0
    pH - 7.5
    didn't check anything else this day

    I KNOW everyone says to check often, but without adding ANYTHING, my chlorine dropped from 7.5, which it was at for a week after my initial shocking, it only dropped to 5.0. I know the TA is a bit high, but I didn't think it was ridiculous and I believe the Calcium is low, but I didn't think it was the biggest deal.

    Last year I used "Yellow Out" for what I believed was Mustard Algae and it worked well after attempting to battle it for a couple weeks (thats primarily because I did think it was pollen). This year the algae is much darker but still "fans" off of the liner like the pollen looking algae from last year, so I don't know how to classify it to treat it.

    When I shocked the pool earlier in the season, I didn't have the test kit, so I started out with a generous amount of powder Cl and added some more two or three times a day until the water was completely cloudy blue.

    Since my CC has always been zero and I am not losing the Cl quickly, I don't know how to accurately shock the pool. I do think that the "growth" was slower when the Cl was 7.5, but it still grew.

    I would LOVE to use my pool on this July 10th and with my Cl dropping so slowly, I didn't want to do anything outrageous this week because with a vacuum, it looks fine with crystal clear water. I might have to wait until after that to do anything to the pool.

    I use a solar cover and I believe that helps with the Cl retention and I only get 4hrs direct sun.

    I appologize for the lengthy post, but I was hoping to give all of the info.

    Thanks,
    -Jay
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  2. Back To Top    #2
    Mod Squad woodyp's Avatar
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    Re: Algae returning on liner

    All your stuff looks just fine. Are we talking brush streaks showing on the SIDES of the pool,..........or on the BOTTOM of the pool? If it's just on the bottom, I'm guessing you might just have some dead algae, super fine dirt, and pollen that keeps settling out. Some of that stuff is very difficult for a sand filter to catch, if that's what you have. You can try the DE trick in pool school too. I'd suggest vacuuming to WASTE an area at a time to avoid too much water loss and see if that thins out the "herd" any. I went thru this same thought process, was sure it was algae at first....decided it was super fine stuff.......and it worked for me. Took mine about a day and a half to fully settle all back out between vacuums. Welcome and good luck!
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
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    Re: Algae returning on liner

    Thanks for the reply...

    I love the DE in the filter, helps with clearing up the blue cloud from the first shock of the season much faster. I am also trying about 1/2 cup in the filter all the time and seeing how quickly that clogs things up.

    The algae is in the corners mostly (from vertical walls to horizontal/slope floor and in the 4 corners of the pool). The liner will go from clean to a slow growth that follows the pattern of the bristles on the brush, almost like a stiff bristled paint brush streak.

    Uncovering the pool today, I found that morst of the bottom and sloped walls were covered. I know I have algae now, just don't know if I need to treat as mustard algae. If memory serves, Pool School doesn't address mustard algae, so I have to do some research on shock levels.

    Poolcalculator.com recommends 16ppm shock level and 29ppm Mustard Algae shock level. That is a lot of bleach and a high chlorine level. Does anyone know if the "yellow out" product or one like it for treating mustard algae has a short life? I was hoping to be on track and swimmable in 7 days if I shock the pool for mustard algae. I am going to shoot for mid to high teens tonight and hope that at least holds me over.

    7/3 Chemicals...
    FC: 3.0
    CC: 0.5
    pH: 7.5

    A day or two ago I could fan the algae of the bottom. Now, I need to apply a bit of pressure to the vac head and make a couple passes.

    I am just bummed by the re-growth...
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  4. Back To Top    #4
    Mod Squad woodyp's Avatar
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    Re: Algae returning on liner

    Pretty sure I've seen the Pros here say that "yellow" out" actually consumes FC at a pretty high rate. There is nothing you can't kill with just a high enough level of FC over time.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

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    Re: Algae returning on liner

    Shocked last night and was at 20.5 FC and less than 0.5 CC this morning. Like I said, poolcalculator.com recommended 26ppm of Cl, so I added a bit more this morning to get up pretty high.

    Very cloudy blue, but definately looks "cleaner".

    I left the solar cover off and will do so all week to help the fc come back down for this weekend.

    pH was 8.2 and TA was 180, but I think I read that the high Cl throws them off.

    Please let me know if any of my actions or logic are incorrect, doing my best to soak in all the knowledge.

    WoodyP, thanks for the multiple replies.
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

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    Re: Algae returning on liner

    More follow up...

    7/4 early afternoon FC was 17

    7/5 morning FC was 15 and CC was less than 0.5

    I used pool calc to bring my FC up to 29 as recommended by poolcalc with 50 CYA for treating mustard algae since I think that was one of my problems.

    After brushing and letting it sit for a day there was white powdery piles laying around the pool floor. They brush up similar to the algae that was on the floor. I am hoping that the white means some/most/all of it is dead. Going to keep FC up for the day and do an OFCLT (overnight free chloring loss test, right?).

    I think my first post was too long to keep anyones interest....
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  7. Back To Top    #7

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    Re: Algae returning on liner

    I just went through the shock process on my pool that I never saw any algae but my SWG could not keep up with the chlorine demand. I held my water at shock level continuously for 5 days and it finally passed the OCLT. Just continue holding the FC at shock levels and keep on brushing and vacuuming. You might want try removing any lights and scrub the niches also. Be diligent and patient.
    16k gal plaster with raised spa, Jandy DEV60 filter, 2 HP 2-speed SHPF Jandy Stealth pump
    Hayward Aqua Rite T-15 SWCG, Jandy LXi 400k BTU NG heater, 350 sq.ft. of Sun Star solar panels, TF-100 Test Kit, Dolphin s300i Cleaner
    Test Kits . Pool Math . Chlorine/CYA Chart . The SLAM Process

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    Re: Algae returning on liner

    Sounds like you are doing the right things. This process can take a little patience. Once you've gone through it you'll have the experience and know what it takes.

    Keep chlorine on hand, keep shock level up there, vacuum regularly, do the OFCLT and you'll be done soon.

    Good luck!

    Choots

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    Mod Squad Bama Rambler's Avatar
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    Re: Algae returning on liner

    Just read all this and you're now doing the right thing. Keep it at shock level for your CYA until you pass the OCLT. Then keep your FC near the top of the recommended range, and never let it get below the min.
    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: Algae returning on liner

    7/5 5:00pm
    FC - 29 and I added 256oz of 6% to keep it above the recommended 29ppm recommended by poolcalc for the rest of the evening and hopefully the night

    6:40pm
    FC - 34 pretty spot on increase according to poolcalculator

    9:40pm
    FC went up to 36-37
    CC - 0.5 or less (turns just the lightest shade of pink and one drop clears it)

    Not a typo, but a hopefully miscounting on my part. I can't explain the increase as I only added bleach at the 5:00 test, not the 6:40 test. I pour the bleach in slowly over the returns and use a "wall whale" to scrub all of the walls and floor before each test because it really moves the water around. I would think that the 1 1/2 hours and wall whale were enough to adequately mix the water with the pump running 24/7. I didn't retest because I just thought, "good, it will kill everything".

    7/6 6:00 AM
    FC 27
    CC appears 0

    This morning with a FC loss of 10, I am hoping that I messed up my counting or that at this high, you can't help but lose it.

    Water is extremely clear and will get slightly white/blue cloudy when I brush as I have not vacuumed it yet, letting the filter do most of the work because brushing is faster than vacuuming.

    I kind of need the pool this Sunday and I am leary of keeping the FC up for another day in hopes of it dropping to a safer level by then and/or adding Cl neutralizer if needed.

    I don't know the other effects the neutralizer has, have never used it to be familiar with amount to use and don't want to pay to remove the Cl I just paid for. Aren't we all doing this to save a bit of money AND have a clear pool?


    Any thoughts...

    Natural OCLT drop with that high of a level or is it really JUST during the day/sun?
    Keep FC up and possibly use Cl neutralizer?
    Let FC start to drop on its own and possibly use Cl neutralizer?
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  11. Back To Top    #11
    Mod Squad Bama Rambler's Avatar
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    Re: Algae returning on liner

    You need to keep it at shock level until you pass the OCLT. Don't worry about trying to get the FC down. It'll come down on it's on soon enough after you've passed it.

    You shouldn't lose any FC at night no matter how high it is. You need to do the tests very carefully at night and the next morning. A miscount of 2 drops and you've failed the test. If you count one more the night before and one less the next morning that's all it takes.

    Keep at it and it'll clear soon. I know it seems like you're spending a lot on it right now but once you're done shocking you'll be surprised how easy and inexpensive it is. Besides, if you were letting the pool store clear it up for you it'd be costing a lot more than a few jugs of bleach.
    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: Algae returning on liner

    Hi, I'm in Central Jersey, too. Yesterday just after I posted that my pool was all clear, I noticed what appeared to be powdery algae on some of the portions of the pool, mostly right at the curve where the walls meet the bottom of the liner. I proceeded to kick it up with my feet while walking around with the vacuum right in the pool. I tested the FC and CC just like you and I had no CCs, so again, I was confused, too. Last night I brought up the FC level higher than I had been holding it at and I think I'm going to be keeping it on the higher range just because the weather has heated up a bit. Maybe the extra sun and heat was just what any stragglers needed to rebloom. Who knows! I just know I don't want it to go over the edge again.

    From what the experts told me in my original thread, it's safe to swim in water up to the shock level for your CYA/FC ratio. So even if your chlorine is on the high side, I don't think anyone's skin or hair will melt off. Hahaha. At least mine hasn't yet!
    26' round AG pool, vinyl liner, 19'' diameter Waterway Sand Filter.
    Central N.J.

  13. Back To Top    #13

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    Re: Algae returning on liner

    Spending money was in reference to buying chlorine neutralizer to counter the chlorine that I just bought. Just thinking out loud.

    Didn't OCLT last night, but keeping FC high to test tonight.

    Once my Cl comes back down to around eight which is the high side of my recommendation, will I be able to accurately test the pH? Also, it was about an eight a day or two ago. Will it go back to pre-shock levels or will acid be needed? The acid doesn't bother me as I need to lower TA.
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  14. Back To Top    #14
    Mod Squad Bama Rambler's Avatar
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    Re: Algae returning on liner

    The pH should go back to pre-shock levels or very close anyway.
    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: Algae returning on liner

    So...

    Water has been crystal clear since Thursday night, but I kept the FC high for another night because I didn't get a chance to OCLT.

    questions:
    1) CYA is 45 and FC is 16 and doesn't come down quickly during the daytime. I am planning a bbq tomorrow with 20 or so swimmers from 2-70.

    2) Any cons to adding CL neutralizer to bring it down to 8ppm, which is the high side of PoolCalculators recommended FC count?
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

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    Re: Algae returning on liner

    Other than cost, there is no issue.

    I would test before the party and swim in it if it were my pool but others will disagree.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Algae returning on liner

    I would swim in it too. I am more concerned about the guests.

    Do you have experience with younger children in the water? I don't want to give anyone any type of skin irritation that causes them not to trust me or my pool.
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  18. Back To Top    #18

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    Re: Algae returning on liner

    So, we swam in it with no apparent ill effects.

    Checked my FC last night and I was at 9.5 and this morning 8.5.

    I understand the basic principals of TroubleFreePool and BBB, but would like to learn the details. Does my FC loss mean shock the pool or there were alot of people in it all day yesterday and the Cl is doing its job?

    -Jay
    20' x 40' / 33,000 gallon / IG / Vinyl
    200lb sand filter / 1hp pump
    4hrs full sun with about 45 min part sun before and after

  19. Back To Top    #19
    kdubya815's Avatar
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    Re: Algae returning on liner

    With that many swimmers, you are sure to see an FC loss as swimmers add organics to the pool. I always try to raise my FC a little above the target when I have several people in it just so I don't go below the minimum. I would do another OFCLT tonight to see where you are. The experts will come along and give you more information. Just wanted to offer a little encouragement! You are doing great!
    18x36 Grecian style vinyl 23,000 gal inground pool, Hayward Pro Series S220T sand filter, Hayward Super Pump 1 hp.

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