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Thread: Getting rid of Algae, new to BBB - could use some help!

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    Getting rid of Algae, new to BBB - could use some help!

    FC - 9.4
    CC - 0.6 (Thanks Pete)
    TC - 10
    pH - 6.6
    TA - 51
    CH - 368
    CYA - 80 (first it's EVER read this high, usually 40-50 and was actually measured at 50 from a different store yesterday)
    H20 - 75 deg., crystal clear but algae in places around the pool and spa in particular

    We opened our pool a month ago and only discovered this site a few days ago. This is my 6th year owning the pool and in the last couple of years the algae has gotten progressively more difficult/expensive to manage and I'm ready for a new approach. After reading up on BBB and ordering my TF100 kit (shipped today), I'm optimistic that I can tame the algae beast once and for all in 2011, but I need some help getting rid of it in the first place so that I can proactively prevent it.

    As I said above, my CYA has never ever tested at 80 so I'm hesitant to read too much into that figure. It was measured at 50 just yesterday and that's a lot more consistent with past test results (that I can find) so for the time being I'm assuming a CYA of 50. With that, my shock FC target is 20.

    Per PoolCalc and TFP, here's my plan:
    - Add 102 oz. baking soda to raise my TA (goal 80) - Have already done this step
    - Add 151 oz. Borax to raise my pH (goal 7.5)
    - Add 330 oz. of 6% bleach to get to shock FC (goal 20)

    Pool store guy also suggested adding 1.5 qts of Scale Inhibitor to mitigate my CH and (as expected) pushed me to purchase a bottle of Banish to hit the algae after I get to shock level. I didn't purchase the Banish but I do have .5 qt of Scale Inhibitor on hand.

    Questions I have are:
    - Should I wait for a period of time between Borax and Bleach steps above?
    - Should I add all 330 oz. of bleach at one time? Or over a period of several hrs?
    - Should I go ahead and do the Scale Inhibitor as well? If so, 1.5 qts or would .5 qt do any good?
    - Am I correct in assuming that TFP members would steer me away from Banish or other algaecides? Or is shock level FC, brushing and filtration going to be enough to get clear of the algae?

    I'm sure I'll have other questions as I go along but for now, that's where I'm at. Any and all input is much appreciated. I'm particularly curious what folks think about my CYA discrepancy, as it could have a pretty big effect on my shock FC target level.

    Sorry for the lengthy first post, just trying to get it all out there to get more specific feedback. Thanks in advance for any advice, I'm happy to have found this site and believe it's going to change my pool ownership experience in a big way.

    - Josh
    15,000G | IG | Plaster | 150 GPM Cartridge Filter | 2HP/2SP Pump

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    JasonLion's Avatar
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    Re: Getting rid of Algae, new to BBB - could use some help!

    Welcome to TFP!

    You appear to have things well in hand.

    Before you add borax it is worth double checking the PH and TA levels to see how they ended up after the baking soda addition, and then redo your borax quantity calculation if needed.

    Wait at least half an hour after adding borax, preferably an hour, before adding bleach.

    I don't see any need for scale inhibitor. Your CH level is not especially high, only just slightly over our recommendations.

    Add the bleach all at once, well pouring slowly but essentially all at once. You will want to test and add more chlorine again as often as practical, up to once per hour. Given that CC is 10, it is likely to take a little while to get everything completely cleaned up.

    How did you get the CYA result? Was that a pool store, or your own test kit. If a test kit, what brand/model of kit?

    CYA will normally only go up dramatically like that if you have been using dichlor to shock. Meanwhile inaccurate CYA test results are fairly common.
    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: Getting rid of Algae, new to BBB - could use some help!

    Thanks for the welcome and the feedback Jason.

    The latest CYA reading of 80 was done at a local pool store, from what I could it was all done electronically in this case. I had it tested yesterday (reading of 50) at a different store and it was done without any electronic involvement that I could tell. I do have an HTH Deluxe Test Kit that is older (came with the house, so 6+ yrs) but haven't done much with it. I don't know how time affects the reagents used in the tests, should I be able to get decent PH and TA readings using this kit? Now I wish I'd ordered my TF100 sooner...

    When adding the bleach all at once, should I be pouring directly into the skimmer (slowly) or around the pool and spa? Or a combination?

    Thanks again.
    15,000G | IG | Plaster | 150 GPM Cartridge Filter | 2HP/2SP Pump

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    JasonLion's Avatar
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    May 2007
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    Silver Spring, MD
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    Re: Getting rid of Algae, new to BBB - could use some help!

    The best way to add bleach is to pour slowly in front of a return jet with the pump running. Both of the other approaches you mentioned are alright, but I prefer the return jet approach.

    I wouldn't count on that CYA reading. Pool stores often make significant errors, and it is a guessing game if the first store got it wrong or the second store got it wrong. Electronic testers don't automatically improve the accuracy, especially if it is an electronic test strip reader, which are especially bad. The best CYA test available is the test where you add a reagent to the pool water which makes it turn cloudy and then see how much is required to obscure a black dot.
    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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    Join Date
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    Re: Getting rid of Algae, new to BBB - could use some help!

    Double check all your numbers after your TF-100 gets there. I'm suspect that your CC may not be as high as that says. I know my local pool store does Free Chlorine and Total Chlorine, you'd actually have to subtract to get the Combined Chlorine number. Any chance that CC - 10 is actually your total chlorine level?

    The good news is that it doesn't change your plan or what JasonLion is telling you. You just might not need to put chlorine in more often than once or twice a day if it's really only .6 instead of 10.

    -- Pete
    32x16 ft Grecian rectangular vinyl pool 8ft on deep end - 19000 gal. 18" Hayward S-240 sand filter. 250K BTU Pentair MasterTemp heater. Hayward 3/4 HP Super Pump.

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    Re: Getting rid of Algae, new to BBB - could use some help!

    There is a very, very good chance of that Pete. I'll dbl check the sheet when I get home but I think you're right and that's a TC value. I'll do a full testing when the kit comes in too.

    Thanks.

    EDIT: You're correct Pete, that was a TC reading of 10. Guess that makes my CC 0.6. Nice catch.
    15,000G | IG | Plaster | 150 GPM Cartridge Filter | 2HP/2SP Pump

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