Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 17 of 17

Thread: black algae spots

  1. Back To Top    #1

    black algae spots

    Hi,
    I did a partial drain of my pool (25k gallon pool) last year being that the tds level was over 3k. I drained about 3/4 if not more.
    This yr again my pool is getting black algae spots though my water clarity is really good. The first and only test from Leslie's indicated that my pool again is at the 3k TDS levels. why? I clean my 4yr old cartridge filter at least twice per year (4 cartridges).....though I usually wait until the water clarity is not there any longer.
    I will get my water tested tomorrow....why do other home owners get away with not draining their water for years and I'm suffering again this year? What gives?

    I will come back with the leslie results tomorrow.

    thanks
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  2. Back To Top    #2
    reebok's Avatar
    Join Date
    Apr 2009
    Location
    Lakeland, FL
    Posts
    1,268

    Re: black algae spots

    what gives is you aren't keeping your water properly balanced. tds is irrelevant. it doesn't matter how high it is, it matters what it is. and chances are you didn't and don't need to drain. we do need a full set of results, but you would do much better to get your own test kit. there are recommendations in pool-school/ but don't be fooled at leslie's if they tell you they have it because they probably don't. I highly recommend you get the kit from www.tftestkits.net and read all the articles under pool chemistry in pool-school/
    this will give you a much greater understanding of your pool and you won't have to deal with the problems you've been having ever again if you follow the outlined methods.
    also, your title is black algae spots but you don't say anything about them? do you have some? I recommend brushing them and rubbing them with a trichlor chlorine tab. it worked in 2-3 days for me when I first found this website and saw that advice.
    16x32 21,000 gallon in-ground exposed aggregate, 1.5hp pump, 120 sqft catridge filter, birdcage, solar panels, aquavac tigershark qc robot.

  3. Back To Top    #3

    In the Industry
    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    28,394

    Re: black algae spots

    Just to reinforce what reebok said, TDS is not important and they are misleading you by telling you it is.

    Your own high quality test kit and the help available on this website will get you started taking control of your pool.

    As well as Pool School, read some of the other threads about folks who came here after having been misled by the pool store......scroll down to the bottom of the thread and read the outcome.....crystal clear water and a balanced, easy-to-maintain pool.

    You can do the same thing if you are willing to test accurately and learn how to use the information from the tests.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4

    Re: black algae spots

    I do have some green/black spots of algae....not a lot.
    Here are my readings as of 1hr ago from Leslie's:

    FAC 0
    TAC 0
    CH 200
    CYA 0
    TA 90
    pH 7.8
    Acid Demand 1
    TDS 3000
    Pho 1000

    They advised to do the following:

    1) add 20 fl oz of muriatic acid
    2) 4rs later add 1/2 gallon of chlorine liquid
    3) 4hrs later add 3lbs of conditioner (cya)

    Please advise if this seems right/wrong?

    my pool water is clear but like I said, some algae spots (specially on my steps).

    thanks in advance
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  5. Back To Top    #5

    In the Industry
    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    28,394

    Re: black algae spots

    Chlorine kills algae....you have none. Even though they advise putting some chlorine in yuor pool, it will quickly be consumed by two things.....the algae in your pool and the sunlight. CYA protects the chlorine from the sunlight but you don't have any of that.....yet

    I suggest you Read the ABC's of Pool Water Chemistry up in Pool School and consider doing your own testing. Also, read How to Shock your Pool because you need to do that as well.

    Leslies advice will help you very short term but your nagging algae issues will soon return.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  6. Back To Top    #6

    Re: black algae spots

    Thanks for the reply.
    I did take a look at the pool school topics and got some info.

    Could you please give me some more detailed suggestions?

    Do I do a shock first (what do I use)? Brush the pool to remove algae (of course) then add the chemicals that they prescribed or is there something more specific you think I should do.

    thanks again for your reply
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  7. Back To Top    #7

    In the Industry
    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    28,394

    Re: black algae spots

    1. Shock your pool in accordance with the procedures outlined in Pool School.

    2. Add enough CYA to get to 40ppm. Use the calculator in my sig to determine how much you will need.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  8. Back To Top    #8

    Re: black algae spots

    it states to bring my FC to shock level. according to your calculator I should add:

    1 gallon 2 quarts or 2 (96 oz) jugs of bleach (to go from 0 to 4).....I have chlorine jugs. is this the same?

    to also add:

    7 lbs of CYA

    I don't' see a combined chlorine reading on the leslie report. is it called something else?

    CAN I just purchase a shock treatment from Orchard/Leslies or is this not the most practical?

    Thanks so much.....
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  9. Back To Top    #9
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: black algae spots

    Quote Originally Posted by jvmagic
    it states to bring my FC to shock level. according to your calculator I should add:

    1 gallon 2 quarts or 2 (96 oz) jugs of bleach (to go from 0 to 4).....I have chlorine jugs. is this the same?
    From zero to 4? Shock level for zero cya is FC 10, not 4.
    What % is the chlorine in your jug?


    to also add:

    7 lbs of CYA

    I don't' see a combined chlorine reading on the leslie report. is it called something else?

    CAN I just purchase a shock treatment from Orchard/Leslies or is this not the most practical?
    The most practical is using bleach or liquid chlorine. The only difference is the % sodium hypochlorite.
    One is simply stronger than the other. Most other 'shock treatments' contain unwanted side effects.

    If we knew the gallons in your pool, we could help verify the Pool Calculator numbers with you.


    Welcome to the forum


    Thanks so much.....
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  10. Back To Top    #10

    Re: black algae spots

    I have a 23k-25k pool.

    The chlorine jug states 12.5% chlorine

    so I will use these chlorine jugs to shock and keep my FC level at 10 (for how long)? how many jugs from 0 to 10?

    I will also be adding 7 lbs of conditioner


    thanks again
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  11. Back To Top    #11
    pitguy3's Avatar
    Join Date
    Jul 2009
    Location
    Birmingham, AL
    Posts
    153

    Re: black algae spots

    Use the pool calculator to determine how many jugs to use... Butterfly has a link to it at the bottom of their post... Otherwise you can just click here... http://www.poolcalculator.com/
    Intex 20x52 above ground pool-
    10600 gallons
    1 man 4 woman Bullfrog Hot Tub
    http://www.flickr.com/photos/pitguy3/se ... 763801706/
    ROLL TIDE!

  12. Back To Top    #12
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: black algae spots

    Quote Originally Posted by jvmagic
    I have a 23k-25k pool.

    The chlorine jug states 12.5% chlorine

    so I will use these chlorine jugs to shock and keep my FC level at 10 (for how long)? how many jugs from 0 to 10?

    I will also be adding 7 lbs of conditioner


    thanks again
    First, lower your pH to 7.5 or 7.6 range. Wait 30 minutes with pump running.

    Second, add enough chlorine to get to FC 10. Using 24K for the pool (& the Pool Calculator):
    Starting with zero in the "now" column & 10 in the "target" column, I get: 1 gallon, 3 qts, & 2 cups of 12.5% LC.

    Then go back and read the Pool School article on How to Shock Your Pool.

    Post back here if you have any qustions. Someone will be around to help.
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  13. Back To Top    #13

    Re: black algae spots

    It seems that all I have to add is chlorine and CYA as a shock treatment based on my current readings and the 'pool school' is it this simple?

    Shocking:

    1. Measure the FC level
    2. Add enough chlorine to bring FC up to shock level
    3. Repeat steps 1 and 2 as frequently as practical, as often as once per hour, and not less than twice a day, until:
    1. CC is 0.5 or lower;
    2. An overnight FC loss test shows a loss of 1.0 ppm or less;
    3. And, if you don't have a FAS-DPD test kit, the water is clear.

    thanks
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  14. Back To Top    #14
    reebok's Avatar
    Join Date
    Apr 2009
    Location
    Lakeland, FL
    Posts
    1,268

    Re: black algae spots

    kind of makes you hate the pool industry doesn't it
    have you added cya yet?
    16x32 21,000 gallon in-ground exposed aggregate, 1.5hp pump, 120 sqft catridge filter, birdcage, solar panels, aquavac tigershark qc robot.

  15. Back To Top    #15
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: black algae spots

    Yep, it's that simple

    The best investment we made in our pool was a good test kit. The best bang for the $ is the TF100 sold by duraleigh at http://www.TFTestKits.net.
    This will put you in control of your pool. It should easily last two years, with proper storage.

    It would be helpful if you put your pool and equipment specs in your sig.
    Go to User Control Panel (upper left under TFP logo) and select Profile, then Edit Sig.

    We'd also like to see a pic of your pool
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  16. Back To Top    #16

    Re: black algae spots

    With minimal effort, it worked!!!!!

    Thank you all for your help. You have been wonderful!
    25k gallon kidney shaped pool
    1 hp pump
    cartridge filter (4 cartridges)
    jandy deck jets

  17. Back To Top    #17
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: black algae spots

    Quote Originally Posted by jvmagic
    With minimal effort, it worked!!!!!

    Thank you all for your help. You have been wonderful!
    Congrats! You are another TFP success story

    Do you have a pic of your pool for us?
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

Posting Permissions

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