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Thread: Can't stop the algae

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    Can't stop the algae

    CYA = 50
    pH = 7.6
    TA = 110

    I'm still fairly new to pool ownership, this is my first full season.

    I've had a couple algae blooms this year and have had to SLAM twice now. I never can seem to completely get rid of the algae. Every single morning there is a thin film on the bottom and sides. According to the CYA/Chlorine chart my minimum chlorine level is 4ppm with a target of 6. I have been keeping it closer to 10 and it has never been below 8 but the algae still keeps growing.

    I'm just about ready to give up and go buy Algaecide and PhosFree to try to get this under control. I hate to declare failure on the whole BBB philosphy but I just can't get rid of the algae. I have never really gotten to crystal clear water yet either. I can see the drains and pattern on the liner in the deep end but it also is just a slight bit cloudy.

    My "pool guy" is telling my my filter is too small and even if I kill the algae the filter will not get rid of all the dead algae. I partially beieve that but last year towards the end of the season I did get crystal clear water so I know the filter can do the job.

    I passed the OCLT last night 8.5 last night, 8.0 this morning after 1.5 hrs of sunlight were already hitting the pool.

    What am I doing wrong?
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Steve-in-VA's Avatar
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    Re: Can't stop the algae

    You're not completing a SLAM if you still have algae present. With your CYA shock level is 20 not 8-10. 20 needs to be maintained and pump running until you have <.5 CC and crystal clear water and passing OCLT. So if you haven't been maintaining a FC of 20 you are just pinning wheels because you're not gaining ground killing algae with keeping your levels at sanitizing level (which needs to be done AFTER algae is killed off). My pool was bad a couple months ago but I've really been trouble free since then. My pool has stayed crystal clear since. This process works but you have to do it right and follow the criteria fully. Hope that helps, since im fairly new to this too

    21,200 gallon/ 30' vinyl round above ground pool/ 200# hayward sand filter/1.5 hp hayward pump (70gl/m) /
    /self installed pool about 3 years ago - Smithfield, VA- Pool filled with well water -TF100 kit

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    Re: Can't stop the algae

    If you still have cloudy water you have not finished your SLAM.

    CC less than .5
    0 FC loss on the overnight test
    CLEAR water (and pool bottom)

    You need to SLAM until all three areas are met.

    Pool School - Chlorine / CYA Chart

    Please note that your FC should be 20 during a SLAM.

    The numbers you are using are for a clear pool.

    What are you using to get your test results?

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    Re: Can't stop the algae

    With a CYA of 50, your SLAM level is 20; did you maintain that level of FC throughout your previous three SLAMS until you passed all three criteria? If not, you have never fully gotten rid of your algae.
    5900 G Fiberglass IG pool (circa 1990), SWG Hayward Aqua Rite GoldLine (2013), IntelliFlo Variable Speed Pump (2013), Hayward Pro Sand Filter (circa 1990), Well water (no iron or other metals fortunately), test with Taylor K2006C, Charleston, SC

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    Re: Can't stop the algae

    OK sounds like I get impatient, nothing new .

    I have not kept the level at 24 until I get crystal clear water. Guess I need to keep it much higher than I have been and just be patient.

    The pool is pretty much brand new as of last August. I got it out of foreclosure and had to replace the liner along with the entire sand bottom. So since it is a new liner Im a little paranoid about bleaching it. My pool guy that did the work last fall got me worried because he said anything over 3ppm will bleach the liner. Although he didn't even check the CYA level and he wants to sell me a new filter for $2000.

    Can you guys give me a little comfort on the level of chlorine and for how long that would lead to the liner being bleached?

    And one other thing, clear seems a little subjective. Wife says it looks fine, I say its cloudy.
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Re: Can't stop the algae

    Different liners use different dyes, so some will naturally fade faster than others. Following the FC/CYA chart is safe for liners, SLAMing in particular is typically much better for a liner than normal 'shocking'. This is because it involves closely monitoring and dosing to make sure it is high enough to kill algae quickly but low enough to not cause problems.

    As for keeping FC above 3 at all times like most of us do, well I have been doing it for 6 years and have not seen any problems. Circumstantial evidence I suppose, but enough for me.

    From my HTC One via Tapatalk
    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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    Re: Can't stop the algae

    Quote Originally Posted by Donldson View Post
    Different liners use different dyes, so some will naturally fade faster than others. Following the FC/CYA chart is safe for liners, SLAMing in particular is typically much better for a liner than normal 'shocking'. This is because it involves closely monitoring and dosing to make sure it is high enough to kill algae quickly but low enough to not cause problems.

    As for keeping FC above 3 at all times like most of us do, well I have been doing it for 6 years and have not seen any problems. Circumstantial evidence I suppose, but enough for me.

    From my HTC One via Tapatalk
    +1.

    I did more damage scrubbing the liner of my last pool trying to get rid of the algae.

    This year I found TFP and my pool looks fantastic, liner and all.

    Dom

    - - - Updated - - -

    Quote Originally Posted by rshackleford View Post
    ......... And one other thing, clear seems a little subjective. Wife says it looks fine, I say its cloudy.
    If you toss a quarter in the deep end can you tell heads or tails standing at the edge?

    If not, I would consider that NOT clear.

    Dom
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    Intex 18' X 48" Ultra Frame AGP 6700 gallons | Two Intex CS8110 SWG's | Hayward Pro Series 21" Sandfilter | Hayward 1.5HP Power Flo Matrix pump | Hayward Thru-wall Skimmer | Wanda the Whale | 72 sq ft of Sungrabber Solar Panels with Hayward GLC-2P-A | Taylor K2006 Test Kit, Sample Sizer & Speed Stir | Click Here To Become a TFP Supporter!

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    Re: Can't stop the algae

    Quote Originally Posted by domct203 View Post
    If you toss a quarter in the deep end can you tell heads or tails standing at the edge?

    If not, I would consider that NOT clear.

    Dom
    You and I have similar standards on water clarity. Right now I'm not sure I can tell its a quarter. Actually after thinking about it, Im not sure I can tell if its a quarter standing on a ladder that is 14' tall. You must have good eyesight.

    I can see the screws on the main drains but I can't tell if they are phillips or straight head.

    Guess I need to go crank up the chlorine level and try to get a proper SLAM done.

    Any estimates on the amount of time it might take?

    Also, no comments were made about the filter. Is it possible to have a crappy filter such that it will never get all the dead algae removed so even if you do a good SLAM and kill all the algae, the water will not become clear? I don't think that is my issue but I was just curious.
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Beens's Avatar
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    Re: Can't stop the algae

    As you said yourself, your pool guy didn't even test cya. If you had 0 cya then 3fc would be fine for maintenance and 20 would be pretty harsh.

    But cya buffers chlorine and makes it less harsh. The cya chlorine chart takes that into account while pool stores and services just pretend cya doesn't exist and lead a lot of people to lovely green or cloudy pools because of it.

    With a cya level of 50 even the 8 FC isn't as harsh as 3fc in a pool with 0 cya.

    What I'm trying to say is, with 50 cya you'd have to go over the mustard algae shock level on the chart and stay that way for a while before you ever had to worry about the chlorine level hurting anything.

    You're safe following the chart and slamming at a level of 20 and that's what it will take to get rid of all that algae.

    Keeping maintenance level FC when you have algae present is kind of like putting some duct tape over a hole in a dam. It might work for a little while but eventually you're gonna lose the battle.

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    Re: Can't stop the algae

    How did the OP get the cya level? I didn't see how the test results were obtained
    10,500 gal IG, Topaz Pebble, auto-level
    Hayward DE filter, 2HP Ecostar VSP, ProLogic PS-4, GVA actuators
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    Re: Can't stop the algae

    Quote Originally Posted by kimkats View Post
    If you still have cloudy water you have not finished your SLAM.

    CC less than .5
    0 FC loss on the overnight test
    CLEAR water (and pool bottom)

    You need to SLAM until all three areas are met.

    Pool School - Chlorine / CYA Chart

    Please note that your FC should be 20 during a SLAM.

    The numbers you are using are for a clear pool.

    What are you using to get your test results?

    Kim
    Im using a Taylor kit that I put together myself. I started out with a FAS only but I added the proper chemicals and other stuff to be able to do a FAS-DPD chlorine test and a CYA test.

    - - - Updated - - -

    Quote Originally Posted by BuckeyeChris View Post
    How did the OP get the cya level? I didn't see how the test results were obtained
    I replied to kimkats post with that info. I basically used a home built kit. I bought the "Wrong" one last year before I found this site. Sicne then I just added the proper chemicals and bottle I needed to do FAS-DPD Chlorine and CYA. FWIW, I was relying on the pool store for my CYA level when this started a few weeks ago and in a period of two weeks I got 4 readings ranging from 25 - 100 on CYA from the same two pool stores. So I bought the necessary stuff to test that myself. Im a slow learner some times
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Re: Can't stop the algae

    Quote Originally Posted by rshackleford View Post
    You and I have similar standards on water clarity. Right now I'm not sure I can tell its a quarter. Actually after thinking about it, Im not sure I can tell if its a quarter standing on a ladder that is 14' tall. You must have good eyesight.

    I can see the screws on the main drains but I can't tell if they are phillips or straight head.

    Guess I need to go crank up the chlorine level and try to get a proper SLAM done.

    Any estimates on the amount of time it might take?

    Also, no comments were made about the filter. Is it possible to have a crappy filter such that it will never get all the dead algae removed so even if you do a good SLAM and kill all the algae, the water will not become clear? I don't think that is my issue but I was just curious.
    Have you tried vacuuming to waste?

    Have you considered adding DE to your sand filter?

    Looking on Hayward's website it looks like the 24" sand filter will flow about 62GPM. At that rate it will take about 10 hours to turn over your pool. I would think running 24/7 during a SLAM would clear that pool.

    Dom
    Dom - TFP Guide
    Intex 18' X 48" Ultra Frame AGP 6700 gallons | Two Intex CS8110 SWG's | Hayward Pro Series 21" Sandfilter | Hayward 1.5HP Power Flo Matrix pump | Hayward Thru-wall Skimmer | Wanda the Whale | 72 sq ft of Sungrabber Solar Panels with Hayward GLC-2P-A | Taylor K2006 Test Kit, Sample Sizer & Speed Stir | Click Here To Become a TFP Supporter!

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    Re: Can't stop the algae

    Quote Originally Posted by domct203 View Post
    Have you tried vacuuming to waste?
    Dom
    Yes. I was vacuuming to waste everyday but that got old quick. So now I am just brushing.

    Quote Originally Posted by domct203 View Post
    Have you considered adding DE to your sand filter?
    Yes. I have been putting DE after every backwashing. I noticed the filter pressure gauge never really goes up much. Starts around 19 and never really gets over 21. After I backwash it seems to work worse. I can see more algae under the returns so it seems to be washing through the filter. The past week I didn't backwash at all, the pressure stayed constant but I saw less algae under the returns. So it seems like the filter works a little better when it gets dirty. Which kind of makes sense.
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Re: Can't stop the algae

    In theory, a SLAM will take at least 2 days because the OCLT must occur over night. In reality, it will probably take at least parts of 3 days because the free chlorine will be oxidizing whatever organics are in the water during night #1, and pass OCLT on the second night, at the quickest.

    Regarding your filter, you want to circulate your pools volume through the filter at least once per day. There should be a sticker on the side of the tank indicating flow rate (volume/minute) of the system. Quick and dirty, dividing your pool volume by the flow rate will give you time in minutes for 1 turnover. Divide again by 60 to convert to hours. If time > 24 hours, then you definitely have too small/less powerful tank/pump because it is impossible to turn over your water once/day. At this point, time to run your pump is really subjective on a number of factors. The main factor, IMO, is how long it takes to circulate your pool once and if you are comfortable with that time. In other words, 12 hours of electricity is more expensive than 5 hours, but a new tank and pump may cost upwards of $2,000 or more.

    I used to run my pump from 7am to 7pm and longer if I was vacuuming or adding chemicals. Once I converted to TFPC and completed my SLAM (during which the pump ran 24 hours/day), I started running it from 1pm.-9pm because it takes 7.91 hours for my water to circulate at least once.
    Chris
    17' x 35' outdoor in-ground Grecian shaped w/ vinyl liner. ≈ 21,000 gallons. Hayward S-200 Sand Filter and 1 HP Hayward Super-pump. Other Accessories: slide, light, ladder, fiberglass stairs, TF-100. Baquacil Conversion - June 2015, SLAM How-to, Chlorine/CYA Chart

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    Re: Can't stop the algae

    Husky25, thanks for the info. I found the sticker and my flow rate is 75GPM so I can turn over the whole pool in a little over 8 hours. Sounds like I should be fine as soon as my SLAM completes.

    I was at 8ppm for chlorine at 8am this morning. I added 2 gallons of chlorine and just tested again it was 14.5. I added 2 more gallons, which will probably overshoot 20 a little but its sunny today so Ill loose some anyway. Ill check again in about 30 mins and hopefully Ill be at 20.

    Thanks for all your help Ill keep you posted on the progress.

    Its already looking clearer!
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Re: Can't stop the algae

    A pool guy (not necessarily aware that he is) misleading you in order to sell you a bigger and more expensive filter and pump? Get out!!!!
    Chris
    17' x 35' outdoor in-ground Grecian shaped w/ vinyl liner. ≈ 21,000 gallons. Hayward S-200 Sand Filter and 1 HP Hayward Super-pump. Other Accessories: slide, light, ladder, fiberglass stairs, TF-100. Baquacil Conversion - June 2015, SLAM How-to, Chlorine/CYA Chart

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    Re: Can't stop the algae

    What is the tolerance in the ppm measurement for the chlorine. Seems like the CYA test is somewhat subjective and since that is the basis for everything else, does the chlorine really have to be at 20 or will 19 be OK? more curiosity at this point.
    38,400 IG chlorine, 24" Hayworth Sand Filter, 1.5HP Pump, 2 skimmers, 2 drains, 2 inlets,Taylor 2006 test kit

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    Re: Can't stop the algae

    ppm may never be exactly 20 (you can't get an accurate reading until about an hour after you add chlorine), but that is the target you want to enter into PoolMath, based on a CYA of 50 ppm for your size pool.

    Chlorine gets diluted immediately as it hits the water, but it takes a little time to distribute throughout the pool. That is why it is recommended to pour in front of a return
    Chris
    17' x 35' outdoor in-ground Grecian shaped w/ vinyl liner. ≈ 21,000 gallons. Hayward S-200 Sand Filter and 1 HP Hayward Super-pump. Other Accessories: slide, light, ladder, fiberglass stairs, TF-100. Baquacil Conversion - June 2015, SLAM How-to, Chlorine/CYA Chart

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    Re: Can't stop the algae

    Add your test kit in your siggy on the bottom. Just put it as a Taylor 2006 as that is what you made it into really.

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    Re: Can't stop the algae

    Quote Originally Posted by rshackleford View Post
    What is the tolerance in the ppm measurement for the chlorine. Seems like the CYA test is somewhat subjective and since that is the basis for everything else, does the chlorine really have to be at 20 or will 19 be OK? more curiosity at this point.
    you're better off rounding up your CYA reading and dosing the CL off of that. better to aim high on the CL, that few extra ppm won't matter so much for the liner but it may delay the SLAM if it's not quite high enough to outpace algae growth.
    10,500 gal IG, Topaz Pebble, auto-level
    Hayward DE filter, 2HP Ecostar VSP, ProLogic PS-4, GVA actuators
    Cal Pools Wave Force Plus (wall return jets plus 2 floor pop-ups), Venturi Skimmer
    Water sheer, 2 wok pots, bubbler stem on the baja step
    ColorLogic Mutlicolor LED lamp. Taylor 2006+speed stir

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