Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 9 of 9

Thread: CYA and FC levels

  1. Back To Top    #1
    TravisD's Avatar
    Join Date
    Jul 2009
    Location
    Tampa, FL
    Posts
    142

    CYA and FC levels

    I had to go to the pool store yesterday to get some replacement parts for my ABG pool. While I was there I was speaking with an employee about how nice my pool has been since I have made the switch from Baquacil to chlorine.
    Anyway, to make a long story short, he basically told me that I am keeping my FC level too high and that I do not need to use a higher level of FC just because I have CYA in the pool. Basically, he was saying the level of CYA has nothing to do with the FC level I need.
    My CYA level is 40ppm and I have been keeping my FC level between 5 and 3 per the CYA / chlorine chart in Pool School.
    He is telling me that I should stay between 1.5 and 3 unless I am shocking. He also said that a 16 FC level for shocking is too high.
    This guy "seemed" genuine and did not try to sell me anything. He was very supportive of the BBB system I am using.
    Now that I have gotten conflicting information in regards to FC level and CYA, I just want my FC level to be right.
    I don't want to be "pool stored" and do the wrong thing. Can someone please reassure me?
    24' Round AGP | 13,600 Gallons | Waterway Cartridge Filter | Waterway 2 Speed Pump | K-2006 Test Kit
    100% Trouble Free Since The Baqua Conversion

  2. Back To Top    #2

    Re: CYA and FC levels

    Does he own a pool?

    Does he run it that way?

    Does he also use algaecide or other chemicals on a regular basis?
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

  3. Back To Top    #3

    In the Industry
    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    28,414

    Re: CYA and FC levels

    Travis,

    There are literally thousands of pools kept just like yours around the country. You should not lose faith in the suggested levels in chem geek's chart. They work.

    Keeping your FC as low as the PS suggests is an algae invitation.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: CYA and FC levels

    Travis, rest assured you are doing the correct thing by maintaining your FC 3 - 5-ish based on your CYA of 40.
    In fact, sounds just like my pool

    Although the pool store person seems genuine, he clearly does not understand the relationship between CYA and chlorine.
    This is all too common an experience for folks going to the pool store.

    Stay confident with the BBB method. It works.
    When your friends'/neighbors' pools start turning, um, green, they may come to you for 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!

  5. Back To Top    #5
    TravisD's Avatar
    Join Date
    Jul 2009
    Location
    Tampa, FL
    Posts
    142

    Re: CYA and FC levels

    Thanks for the reassuring words everyone! I have gotten so much great information off this site that I was confident I was right, but he put that little bit of doubt in my head.
    So he is wrong for saying that you do not have to increase FC levels in relation to CYA levels, right?
    24' Round AGP | 13,600 Gallons | Waterway Cartridge Filter | Waterway 2 Speed Pump | K-2006 Test Kit
    100% Trouble Free Since The Baqua Conversion

  6. Back To Top    #6
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: CYA and FC levels

    Correct, you do need to raise FC levels as the CYA level goes up (unless you want to have problems, which will force you to go to the store more often and spend extra money on things from the store to solve your problems).
    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

  7. Back To Top    #7

    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    12,085

    Re: CYA and FC levels

    Travis,

    If this guy at the pool store knows any chemistry at all (which he may not), have him look at this paper which definitively determined the chlorine/CYA relationship.

    There are also more links to additional scientific studies showing the relationship of chlorine and CYA in this post.

    You might ask him why he believes there isn't any relationship. Is this something he was told by a manufacturer's rep?

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  8. Back To Top    #8
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    Re: CYA and FC levels

    You can not refute scientific research and data. One fact he did leave out, follow his advice and you'll have a backyard algae farm in no time. Maybe the real inspiration behind his genuine act...you come back to buy lots of chemicals to combat your green pool.
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  9. Back To Top    #9
    TravisD's Avatar
    Join Date
    Jul 2009
    Location
    Tampa, FL
    Posts
    142

    Re: CYA and FC levels

    Alright, thanks again for reassuring me that I'm doing the right thing. I am now 100% convinced that he has no idea what the relationship is between FC and CYA. I might even print that up and give him some reading material if I see him again.
    Thanks again for setting me straight!
    24' Round AGP | 13,600 Gallons | Waterway Cartridge Filter | Waterway 2 Speed Pump | K-2006 Test Kit
    100% Trouble Free Since The Baqua Conversion

Posting Permissions

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