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Thread: Do I need to adjust anything?

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    Do I need to adjust anything?

    We have been fighting black algae for 3 weeks. After I found this site I stopped listening to the pool store guys which helped a lot. Before then we had a CYA level of 250 which they said was OK. We partially drained our plaster pool and refilled. Next we did several days of shocking in the 35 - 40 ppm range until stopped losing FC overnight and then maintained FC at that level for another 3 days. I was using the DPD extreme FC test to determine FC.

    We still have black spots but none seem to have the slimy top coat any more plus we are continuing to use SS brush to brush daily.

    I finally was able to afford the full test kit and I have some new numbers and would like input on whether I need to adjust anything at this time.

    FC 21.5 (1 ppm drop last night) - planning to maintain FC at 12 based on CYA of 100
    CC 0.5
    pH ?? reads 7.5 but FC levels are high so not accurate right?
    TA 110 - is this accurate at high FC levels? Turns blueish color instead of red
    CH 250 - had to add reactant before doing test to get the right color and no little specks in the
    water - does this mean I should be testing for other metals?
    CYA 100 - pool store told me it was 50 three times. Should I do another partial drain or is this OK?

    Thanks,

    Patricia
    15,000 IG, White plaster, Cart filter, Jet Vac sweep
    17,000 gal IGP, White plaster, Hayward Swimclear Cartridge Filter system, Sta-Rite Max-e-pro 1/2 hp pump; 3/4 hp booster pump

    Sacramento, CA

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    Re: Do I need to adjust anything?

    Patricia,

    It looks like you are getting a grip on what your pool needs.

    I would suggest you do one more drain and try to get that CYA down into a manageable 40-60 range. (I assume you are manually chlorinating) That lower CYA will let you put your FC in the 10-12 range and it will still be very effective at killing the remaining black algae.

    Additionally, it will allow your pH test to be more accurate. In short, everything is better when your CYA is well below 100.

    Don't worry about your T/A......that test stays good.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  3. Back To Top    #3

    Re: Do I need to adjust anything?

    Thanks Dave.

    I'll have to wait til the weekend to do the partial drain when I can get help doing it during the day. Until then I guess I'll keep the pool FC around 20 to make sure the algae stays dead.

    I had one more question about the CH test results.

    I had to add reactant before I did the rest of the test or I got little purple floaties and almost no color change. I found this suggestion posted elsewhere on TFP by waterbear. Worked perfectly.

    I want to know if this means I should be testing for other minerals besides calcium?

    Patricia
    17,000 gal IGP, White plaster, Hayward Swimclear Cartridge Filter system, Sta-Rite Max-e-pro 1/2 hp pump; 3/4 hp booster pump

    Sacramento, CA

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