Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 11 of 11

Thread: Green Water

  1. Back To Top    #1

    Join Date
    Oct 2011
    Location
    Mebane, NC
    Posts
    19

    Green Water

    I don't close my pool during the winter. Yesterday I vacuumed the pool. The water was blue but it did need vacuuming. The FC was 0, so being that it was temperature was warming up, I added some bleach. The TA was 70, so brought it up to 100 overnight.

    Today the water is GREEN! The pH was 8.2 (from adjusting the TA) so I used pH decreaser and it came down to 7.4. I decided to shock the pool and with a CYA of 25/30, I put bleach in and now have FC of 12. CC=0.

    Am I doing the right thing to get the water clear? Thanks in advance!
    20 x 40 IG 26,000 gal. vinyl
    Hayward sand filter S244T 62 GPM
    Hayward 2.0 hp Super Pump Mdl SP2615X20
    T-100 Kit
    Pool School

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Green Water

    That depends on what kind of green. Was it a clear transparent green, or was the pool at all murky or hazy?
    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

  3. Back To Top    #3

    Join Date
    Oct 2011
    Location
    Mebane, NC
    Posts
    19

    Re: Green Water

    Hey, Jason Thanks for replying. It is clear transparent green.
    20 x 40 IG 26,000 gal. vinyl
    Hayward sand filter S244T 62 GPM
    Hayward 2.0 hp Super Pump Mdl SP2615X20
    T-100 Kit
    Pool School

  4. Back To Top    #4

    Join Date
    Oct 2011
    Location
    Mebane, NC
    Posts
    19

    Re: Green Water

    Jason - I just went out to take another look. From the deck, I can see to the bottom at the shallow end. However, I cannot see the bottom at the deep end. When I'm at the edge of the pool, I can see the bottom at the deep end.
    20 x 40 IG 26,000 gal. vinyl
    Hayward sand filter S244T 62 GPM
    Hayward 2.0 hp Super Pump Mdl SP2615X20
    T-100 Kit
    Pool School

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Green Water

    From your description it is very likely to be metals coloring the water rather than algae. Metals in the water, typically iron or copper, can turn the water a clear transparent green, especially when the PH is going up for some other reason at about the same time.

    It is possible for algae to tint the water green before the algae is really obviously visible. Though if that was the cause I would expect the FC level to be falling quickly, and I would expect that adding extra chlorine would clear it up immediately. Metals in the water will turn even more green if you add extra chlorine.

    The treatment for metals turning the water green is to lower the PH, let the FC level come down to normal, and if it doesn't clear up fairly quickly, add a startup dose of sequestrant.
    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

  6. Back To Top    #6

    Join Date
    Oct 2011
    Location
    Mebane, NC
    Posts
    19

    Re: Green Water

    So I should just let the FC fall from 12 to 2-3? This could take awhile without sunshine, right? Is that OK? The pH is about 7.4 right now. Should I lower it more? Not sure what sequestrant is???
    20 x 40 IG 26,000 gal. vinyl
    Hayward sand filter S244T 62 GPM
    Hayward 2.0 hp Super Pump Mdl SP2615X20
    T-100 Kit
    Pool School

  7. Back To Top    #7
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Green Water

    Quote Originally Posted by bjthon
    So I should just let the FC fall from 12 to 2-3? This could take awhile without sunshine, right? Is that OK? The pH is about 7.4 right now. Should I lower it more? Not sure what sequestrant is???
    pool-school/metal%20stains
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  8. Back To Top    #8

    Join Date
    Oct 2011
    Location
    Mebane, NC
    Posts
    19

    Re: Green Water

    Jason - just wondering how metals can get into the water? We orginially filled the pool with city water brought in. For the past 1 1/2 years I've been topping if off with our well water (which has low iron and copper) as well as rain water. Just wondering!
    20 x 40 IG 26,000 gal. vinyl
    Hayward sand filter S244T 62 GPM
    Hayward 2.0 hp Super Pump Mdl SP2615X20
    T-100 Kit
    Pool School

  9. Back To Top    #9

    Join Date
    Jun 2012
    Location
    Howell, NJ
    Posts
    977

    Re: Green Water

    Some trichlor tablets contain copper. Some algaecides also contain copper. The other possibility I know is a mineral system. Have you been using any of these? Just wondering, how do you know your well water has low metals? Did you actually have it tested?
    John
    7 year old ~13,500 gal 24' AGP with 1.5 hp Proline pump, 150 sqft Pleatco cartridge, filled with well water with pH of about 4.5.
    Wanda the Whale pool vacuum, home made heater, Taylor K-2006
    Cloudy Pool? 1) Order test kit. 2) Follow SLAM
    New to TFPC? Read Pool School a few times, then post questions. PoolMath will help with chemical additions.

  10. Back To Top    #10
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Green Water

    Iron tends to come from well water. Copper is in some kinds of algaecide and is also put into the water by ionizers and mineral systems. Copper can also get into the water if the PH is way too low and you have a heater with a copper heat exchanger (which is common).

    Iron turns the water yellow, which often looks green against a blue pool surface. Copper tends to turn the water a bright emerald green.
    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

  11. Back To Top    #11

    Join Date
    Oct 2011
    Location
    Mebane, NC
    Posts
    19

    Re: Green Water

    Quote Originally Posted by JohnN
    Some trichlor tablets contain copper. Some algaecides also contain copper. The other possibility I know is a mineral system. Have you been using any of these? Just wondering, how do you know your well water has low metals? Did you actually have it tested?
    Hi John ~ No, have not used any of items mentioned. Yes, I did have my water tested. Copper was <0.05 mg/l and iron < 0.10 mg/l - both below "not to exceed" levels.
    20 x 40 IG 26,000 gal. vinyl
    Hayward sand filter S244T 62 GPM
    Hayward 2.0 hp Super Pump Mdl SP2615X20
    T-100 Kit
    Pool School

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •