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Thread: Algae driving me nuts!

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    Algae driving me nuts!

    OK....I've had the pool for 8 years and have never had the problem I have today even when the balance was off a bit. Right now, PH is about 7.6, chlorine is 11, and alkalinity is 100. 2 days ago after shocking on Saturday, the chlorine was at 15 with PH of 8.2. Monday, I added 1/2 gal acid and removed tabs from chlorinator. Have brushed about 4 times in last few days and it just keeps coming back!!! I don't get it. The pool store is telling me I should add PhosFree, but I have never had to to that before and after reading on this Forum, it sounds like the phosphates diatribe is not real. But yet.....I still have stinkin algae! so now I am wondering if I should try the Phosfree. Any thoughts out there in Pool Land?!

    Thanks!

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    Mod Squad woodyp's Avatar
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    Re: Algae driving me nuts!

    Welcome...and scratch the phosphate remover. The most important # you didn't give us is CYA. You should order one of our recommended test kits. WHAT are you shocking with? I'll bet good money it's got even more CYA in it.
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    Re: Algae driving me nuts!

    Two things you said concern me, tabs and shock. Any solid form of chlorine, such as tabs and shock powder, add CYA (aka stabilizer) to your pool. Your FC level needs to stay above 7.5% of whatever your CYA level is to keep algae at bay, and once algae has taken hold, you have to raise FC to 40% of your CYA and keep it there until it is all dead to get rid of it.

    If you've been using tabs to chlorinate your pool, chances are your CYA is extremely high. So even though FC of 15 sounds like a lot, if your CYA is over 200 that is still not enough chlorine to keep algae from growing. This is why we only add CYA up to the level required, and then use only CYA free products to chlorinate such as liquid chlorine, aka laundry bleach.

    You'll need to get a good test kit to get an accurate CYA reading in order to know how much chlorine you need to maintain in your pool. Do not rely on pool store testing for this, they are terribly inaccurate. And test strips are worthless.

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    funandsun's Avatar
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    Re: Algae driving me nuts!

    if FC was 15, your pH reading is suspect too and you may have just corrected something that didn't need to be corrected. yikes.
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    Re: Algae driving me nuts!

    Quote Originally Posted by jeffchap View Post
    Two things you said concern me, tabs and shock. Any solid form of chlorine, such as tabs and shock powder, add CYA (aka stabilizer) to your pool. Your FC level needs to stay above 7.5% of whatever your CYA level is to keep algae at bay, and once algae has taken hold, you have to raise FC to 40% of your CYA and keep it there until it is all dead to get rid of it.

    If you've been using tabs to chlorinate your pool, chances are your CYA is extremely high. So even though FC of 15 sounds like a lot, if your CYA is over 200 that is still not enough chlorine to keep algae from growing. This is why we only add CYA up to the level required, and then use only CYA free products to chlorinate such as liquid chlorine, aka laundry bleach.

    You'll need to get a good test kit to get an accurate CYA reading in order to know how much chlorine you need to maintain in your pool. Do not rely on pool store testing for this, they are terribly inaccurate. And test strips are worthless.
    Please read this again it is concise, sound advice and I have no doubt is the reason for your frustration.
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    Divin Dave's Avatar
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    Re: Algae driving me nuts!

    my money says your CYA is way too high for the chlorine to be effective.

    1. Order a good test kit. Either the TF100 XL (most recommeneded because it suits home owners better), OR the Taylor K2006C (must be the C model). No other test kit is going to provide you what you need.
    2. Read Pool School on the pool chemical balance recommendations. If you follow them you will never have another problem.
    3. Read Learn how to SLAM in pool school. Its not hard, but patience is a must.
    4. When your test kit arrives, test your water. Adjust for CYA if its above recommended levels.
    5 SLAM

    Do 2 through 4 while you're waiting on your test kit. And ask questions about CYA and FC relationship so you understand, that its a critical one. And ask more questions about slamming.
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
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    Re: Algae driving me nuts!

    Okay thanks....I'll be ordering test kit pronto. thanks very much everyone!

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    Re: Algae driving me nuts!

    Here's the latest analysis that I got today from pool store: FC - 3.8, TC - 4.2, PH - 7.9, TA - 31 (real low), CYA - 37. I still have some algae that showed up overnight. Will be going through the Pool School steps, but thought I'd see what y'all thought about these results. am adding baking soda shortly to raise the alkalinity. thoughts? thanks a bunch!

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    kellyfair's Avatar
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    Re: Algae driving me nuts!

    I wouldn’t add anything but chlorine until you get your test kit and know your numbers for sure.
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    Re: Algae driving me nuts!

    TA and pH for the most part have nothing to do with your algae problem. Algae is almost always the result of too little FC. If your FC is correct, and that's debatable as these are pool store results, then it's likely that your CYA is much higher than 37. This is even more likely since you've been using tabs to chlorinate, and tabs add CYA to your water every time you put one in.

    Use only liquid chlorine from now on, and add a gallon per day until your test kit arrives. We can't really be any more specific than that until we have a CYA number we can believe. Until then, you're in a holding pattern.

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    Re: Algae driving me nuts!

    Roger that! thanks!

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    Re: Algae driving me nuts!

    I'll wait to get your test kit. Once you get your test kit, measure the levels for FC, CC, CYA, pH, TA, and maybe CH.... what type of pool do you have? Could you put that information on your signature page.

    Quote Originally Posted by Slider52 View Post
    Here's the latest analysis that I got today from pool store: FC - 3.8, TC - 4.2, PH - 7.9, TA - 31 (real low), CYA - 37. I still have some algae that showed up overnight. Will be going through the Pool School steps, but thought I'd see what y'all thought about these results. am adding baking soda shortly to raise the alkalinity. thoughts? thanks a bunch!
    16x32 IG Pool (2FT Radius) & Hayward H-Series Heater, Non-SWCG Pool,Blue Vinyl Liner & 15,000 Gallon Capacity & Single Pump Speed, Hayward High Rate Sand Filter & Vari-Flo XL, Hayward UV Sterilizer & Automatic Chlorine Feeder, Hayward MaxFlo XL Pump & ColorLogic LED, TF-100. Links: FC/CYA Recommended Chemical Levels, SLAM - Shock Level and Maintain, Pool School - Basic Pool Care Schedule

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    Re: Algae driving me nuts!

    Hello again everyone.....got my TF100 and here's what I have after meticulously testing: FC - 16, CC - 0, Ph - 8.5, TA - 240, CYA - 100, CH - 775 (hard well water to be taken into account?)
    15,587 gallon gunite
    I added acid and got PH to 7.5 and TA to 190. brushed yesterday....algae came back during the day today. Thoughts?
    15,587 gallon free-form gunite with spa
    Jandy Filter DE-L60 w/Stealth SHPM 2.5 pump
    LT Heater - model unknown
    Well water
    TF-100 test kit with speedstir

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    Re: Algae driving me nuts!

    You’ve got algae, so you need to SLAM. Your CYA is high, see this chart. Would be easier to SLAM if your CYA was lower... is it possible for you to do a partial drain and refill?
    16' by 4' Intex Ultra Frame AGP
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    Re: Algae driving me nuts!

    The only way I can drain the pool is via backwashing into my yard....with FC level at 16 I don't really want to put on to my lawn. Question: I don't understand raising the FC when it is already at 16. the chart shows that I want an FC range of 11-13 with CYA of 100. Is the answer to shock the heck out of it due to the presence of algae? Wonder why the algae is present in the first place with FC so high?

    - - - Updated - - -

    Btw, the water is crystal.
    15,587 gallon free-form gunite with spa
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    LT Heater - model unknown
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    kellyfair's Avatar
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    Re: Algae driving me nuts!

    That’s your normal FC when your pool water is healthy and clear. Since algae has set in, this means your chlorine hasn’t always been higher enough to prevent the algae, and now that you have it, you will need to maintain FC at 39 to clear the algae.

    You can see why it’s easier to SLAM with lower CYA.

    - - - Updated - - -

    I bet it isn’t crystal when you brush and stir it up!

    By the way, your FC right now is too high to get a correct reading on PH. I wouldn’t add any more acid until you drop your FC to 10 or less, then test PH.
    16' by 4' Intex Ultra Frame AGP
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    Re: Algae driving me nuts!

    Wow...ok...over the past 8 years, the FC has been maintained at much lower levels without algae showing up....that's what has me scratching my head. But.....am ready to SLAM the heck outta this dang algae I'll tellya. I am new to the use of bleach and have tried using the pool math calculator to figure how much to add in this case. Can you please gimme a hint? Thanks so much!

    - - - Updated - - -

    Wow...ok...over the past 8 years, the FC has been maintained at much lower levels without algae showing up....that's what has me scratching my head. But.....am ready to SLAM the heck outta this dang algae I'll tellya. I am new to the use of bleach and have tried using the pool math calculator to figure how much to add in this case. Can you please gimme a hint? Thanks so much!

    - - - Updated - - -

    you know.....you're right....i just came in from brushing and yep....it's a bit cloudy now. Copy that on the PH test.
    15,587 gallon free-form gunite with spa
    Jandy Filter DE-L60 w/Stealth SHPM 2.5 pump
    LT Heater - model unknown
    Well water
    TF-100 test kit with speedstir

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    Re: Algae driving me nuts!

    It’s going to be seriously hard to do the SLAM with your CYA as high as it is. For example, right now, to get to 39, you would have to add 3.5 gallons of 10% bleach. And for the SLAM, you have to keep it at 39 as much as you can.

    If you are nervous about draining with FC at 16, I think I would let the FC go down lower, so I could drain AND get an accurate PH.
    16' by 4' Intex Ultra Frame AGP
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    DeanP66's Avatar
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    Re: Algae driving me nuts!

    The reason you're having problems now is that your CYA has built up over time. When it's in proper range (30-50), FC can be maintained at much lower levels and get the job done. As CYA climbs, it becomes much harder and requires more and more FC to do the same job. CYA usually climbs because people chorinate with tablets, powdered shocks, or granular chlorine. That's why we recommend using nothing other than liquid chlorine or bleach. They don't add any CYA.
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    Re: Algae driving me nuts!

    you know.....you're right....i just came in from brushing and yep....it's a bit cloudy now. Copy that on the PH test.

    - - - Updated - - -

    oh wow.....so the tabs and granular shock is the culprit for this gross imbalance?!!! man oh man....you guys are really educating this pool worm....lol. So how do i calculate how many gallons of bleach to add each to maintain or in this case to SLAM?

    - - - Updated - - -

    I wonder how much water I would need to drain to get the CYA down a bit to SLAM?
    15,587 gallon free-form gunite with spa
    Jandy Filter DE-L60 w/Stealth SHPM 2.5 pump
    LT Heater - model unknown
    Well water
    TF-100 test kit with speedstir

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