Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 14 of 14

Thread: Why use tablets if they increase CYA?

  1. Back To Top    #1

    Join Date
    May 2014
    Location
    Illinois
    Posts
    10

    Why use tablets if they increase CYA?

    I'm fairly new pool care and I've seen tons of posts regarding high CYA levels.

    I plan on shocking my pool with Sodium Hypochlorite (liquid chlorine) to open it. Why not just shock it every week with this stuff to keep chlorine levels up?

    How is everyone keeping the CYA from getting too high if you're using tablets every week? Is there any reason I can't liquid shock every week instead of using chlorine tabs? Or is there a way you all use tablets and still keep CYA down?

  2. Back To Top    #2

    Join Date
    Jun 2013
    Location
    East TN
    Posts
    309

    Re: Why use tablets if they increase CYA?

    I use tablets when going on vacation because it will keep the chlorine up for a few days while your not there. Bleach needs to be added everyday. If your CYA is low you can use tablets to raise it back up. If its too high then all you can do is drain water. If you use the tablets (tri-chlor) all season or di-chlor shock then its going to raise the CYA way up there. In other words, if your CYA is where you want it then use bleach unless you cant add it every day.
    18,000 Gallon Aboveground. Sand Filter with 2HP 2 speed Pump.

  3. Back To Top    #3
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,089

    Re: Why use tablets if they increase CYA?

    Why shock at all? Shocking weekly is unnecessary. Just add enough chlorine daily to maintain your FC level and the pool will stay clear and safe. No need to shock. Tablets are convenient, but the CYA increase rules them out for much but vacation use.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  4. Back To Top    #4

    Re: Why use tablets if they increase CYA?

    Hello and welcome to the forum. Sounds like you are seeing the problem that trichlor tablets create. If you have a short swim season, or your pool gets a lot of water/snow during the winter to dilute CYA, or you backwash your filter frequently (and water is cheap and plentiful) then using tablets may be OK. But a great many pools are NOT so diluted, backwashed, or short seasoned enough to manage on tablets all the time.

    Here at TFP we know that when you open your pool, you really need to accurately test the water to see WHAT it needs.

    It may be that the CYA you had last year is still there. It may be that it has all gone away. If you add liquid chlorine and CYA is very high, it may not be enough to actually sanitize the pool. If you add liquid chlorine and CYA is very low, it could damage your liner, for example, or simply be wasted as it decays due to sun exposure without the protection of stabilizer in the pool.

    Without a good water test you are flying blind.

    As regard shocking weekly, if you keep the chlorine level stable by testing and adding smaller amounts more often, you will not need to shock the pool. Many of us rarely shock the pool. I think I did it once about this time last year. I did it once when some vultures left something nasty in the hot tub. I did it once when I found a dead baby squirrel in the pool. So, about once a year on average and that is in response to a specific problem, or sometimes it is due to my own general laziness letting the chlorine go to zero early in the spring when I am not used to monitoring the pool regularly. (Here in TX I never close the pool, but do slack off to testing every few weeks in winter and I have to remember to get back to regular testing by May.)

    If you read Pool School, you will grasp the chemical interactions that are going on in your pool. Regular testing will tell you what is changing and the Pool Calculator will tell you what you need to add to the pool.

    While trichlor tablets are EASY, they are a luxury that some of us cannot afford due to the constant build up of stabilizer. In my pool, tablets will over-stabilize my pool in just 2 weeks of constant use. I have to use liquid chlorine most of the time to avoid that.

    I've already taken a 2 week trip this spring and so while the CYA level was quite low from our wet winter, 2 weeks of tablets has put it at the top of the safe range now. Any later vacation will likely not be so easy for the pool sitter as he will have to test and use bleach 3x/wk instead of just loading the auto feeder once a week. If it keeps raining like it has, maybe CYA will decline some by the next trip. The testing will tell. In the meanwhile, I use jugs of bleach or liquid shock, and muriatic acid as needed based on testing every other day or so.
    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.

  5. Back To Top    #5
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Why use tablets if they increase CYA?

    Quote Originally Posted by Crawnos View Post
    I'm fairly new pool care and I've seen tons of posts regarding high CYA levels.

    I plan on shocking my pool with Sodium Hypochlorite (liquid chlorine) to open it. Why not just shock it every week with this stuff to keep chlorine levels up?

    How is everyone keeping the CYA from getting too high if you're using tablets every week? Is there any reason I can't liquid shock every week instead of using chlorine tabs? Or is there a way you all use tablets and still keep CYA down?
    Welcome!

    There's no reason you can't shock with bleach every week, if you want to. It won't hurt anything but your wallet. A whole bunch of us just use bleach to maintain our chlorine levels every day and we never need to "shock". Not for years, and a lot of us never actually close our pools, the water's just too cold to swim in and it costs too much to heat. http://www.troublefreepool.com/threa...AM-free-thread
    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!

  6. Back To Top    #6
    Divin Dave's Avatar
    Join Date
    Oct 2013
    Location
    Longview, Texas
    Posts
    4,926

    Re: Why use tablets if they increase CYA?

    Hi welcome to TFP!
    No one who maintains there pool using the TFPC method uses tabs for regualr chlorine maintenance. They can be useful under certain circumstances.
    It would be helpful for you to understand the TFPC method by reading Pool School.
    http://www.troublefreepool.com/content/

    Quote Originally Posted by Crawnos View Post
    I'm fairly new pool care and I've seen tons of posts regarding high CYA levels.

    I plan on shocking my pool with Sodium Hypochlorite (liquid chlorine) to open it. Why not just shock it every week with this stuff to keep chlorine levels up?

    How is everyone keeping the CYA from getting too high if you're using tablets every week? Is there any reason I can't liquid shock every week instead of using chlorine tabs? Or is there a way you all use tablets and still keep CYA down?
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

  7. Back To Top    #7

    Join Date
    May 2014
    Location
    Illinois
    Posts
    10

    Re: Why use tablets if they increase CYA?

    Wow I didn't expect to get a response that fast, thanks everyone. I've gone through Pool School and it seems like the idea is to Slam to start the season and then check daily or every other day for what needs to be adjusted to get FC based on that calculator in this site.

    I've always been under the impression that BOTH liquid chlorine and tablets have been needed. So all I really need is Sodium Hypochlorite (chlorine/bleach) to Slam and then use a little bit daily based on test results. I guess I've always thought tablets were needed because pool stores stock them so much and they seem like a common thing people have in their pools.
    32'x16', 14K gal, AG vinyl, sand

  8. Back To Top    #8
    Divin Dave's Avatar
    Join Date
    Oct 2013
    Location
    Longview, Texas
    Posts
    4,926

    Re: Why use tablets if they increase CYA?

    Quote Originally Posted by Crawnos View Post
    Wow I didn't expect to get a response that fast, thanks everyone. You're welcome! I've gone through Pool School and it seems like the idea is to Slam to start the season not necessarily. It depends on test results of the water. There are plenty of us TFPCer's who dont need to slam to start the season.and then check daily or every other day for what needs to be adjusted to get FC based on that calculator in this site. That's exactly right!

    I've always been under the impression that BOTH liquid chlorine and tablets have been needed. nope. So all I really need is Sodium Hypochlorite (chlorine/bleach) to Slam and then use a little bit daily based on test results. Providing you actually do need to slam, that's right! I guess I've always thought tablets were needed because pool stores stock them so much and they seem like a common thing people have in their pools.
    Tabs are indeed probably the most commom pool product sold. Why? Pool Stores are in business to sell stuff. Whether you need it or not. It's their job to do that. Just because a Pool Store says add this or add that, or have it stocked in their store does not mean you need it! It's all about marketing. "Drop one in and bring us your water to test once a week and we will tell you what to buy". Good Gosh! What could be easier? Right? There is no real chemistry science used in the pool store. Its all hype with a high price tag. Most people have no clue about pool water, so they are at the mercy of the pool store...until they come here....

    To be fair though. There are some pool stores, and people who work in them, that are actually pretty good, but they are few and far, far, far between.
    Some of them along with many more other Pool Industry Professionals are active members of this forum.
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

  9. Back To Top    #9
    Casey's Avatar
    Join Date
    Apr 2007
    Location
    SW PA
    Posts
    10,157

    Re: Why use tablets if they increase CYA?

    And the truth comes out... you are becoming informed! Welcome to TFP!

    P.S. I did not SLAM my pool this Spring!
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

  10. Back To Top    #10

    Re: Why use tablets if they increase CYA?

    Quote Originally Posted by Crawnos View Post
    Or is there a way you all use tablets and still keep CYA down?
    The only practical way to lower CYA is to dilute the pool water when the cyanuric acid levels get too high.
    And, just in case you haven't read that part yet, the higher the CYA levels, the higher you need to keep your FC levels for the same amount of sanitation activity.
    Silicon Valley, 38,500 gallons in-ground plaster; Sta-Rite System 3 Model S8M150, 259 sqft cartridge 25022-0203S + 191 sqft cartridge #25021-0202S = 450 sqft filter@0.28gpm/sqft = 125 gpm@50psi max. Three 220v Sta-Rite Max-e-Glas II pumps {AO Smith QC1102 1.0x1.65SF for filter + cleaner; SQ1152 1.5x1.47SF for spa jets; square 48Y flange}. 13 Fafco 12'x4' professionally installed "Revolution" solar heating panels + Raypak RP2100 P-R 405A-EP LPG 399,000/hour heater + Compool Lx3600 controller + Infinity 4000 automatic pool cover (120v 3/4 HP motor); both skimmers are NOT filtered & serve only as intake for 9-port water valves (aka cleaner heads) controlling fifteen Paramount PCC2000 3" self-cleaning jets with the optional Debris Containment Canister.

  11. Back To Top    #11
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: Why use tablets if they increase CYA?

    Quote Originally Posted by Crawnos View Post
    I've always been under the impression that BOTH liquid chlorine and tablets have been needed. So all I really need is Sodium Hypochlorite (chlorine/bleach) to Slam and then use a little bit daily based on test results. I guess I've always thought tablets were needed because pool stores stock them so much and they seem like a common thing people have in their pools.
    Welcome to TFP!

    You need FC to keep a pool safe, clear, and Algae free. Where it comes from, is not as important as understanding what else is in those sources, and what side effects those sources may cause. No pool needs more than one source of FC, as long as it gets the FC.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

  12. Back To Top    #12
    bridgman's Avatar
    Join Date
    Mar 2014
    Location
    Bowmanville, ON Canada
    Posts
    461

    Re: Why use tablets if they increase CYA?

    I guess you could say tabs are like fast food -- convenient for the seller (they don't degrade like liquid chlorine), convenient for the buyer (tabs dissolve slowly so you can theoretically ignore the pool for several days at a time), but unhealthy over time (CYA buildup makes the recommended FC level ineffective over time so things start to grow in your pool).

    As with fast food, the business works because your (pool's) health is the buyer's problem not the seller's problem, and only the sellers operate with a long planning horizon
    Cedar hot tub, 680 US gallons - Snorkel wood-burning heater, canoe paddle, "offline" Intex 1000 GPH pump/filter with skimmer

  13. Back To Top    #13
    Divin Dave's Avatar
    Join Date
    Oct 2013
    Location
    Longview, Texas
    Posts
    4,926

    Re: Why use tablets if they increase CYA?

    excellent analogy!!

    Quote Originally Posted by bridgman View Post
    I guess you could say tabs are like fast food -- convenient for the seller (they don't degrade like liquid chlorine), convenient for the buyer (tabs dissolve slowly so you can theoretically ignore the pool for several days at a time), but unhealthy over time (CYA buildup makes the recommended FC level ineffective over time so things start to grow in your pool).

    As with fast food, the business works because your (pool's) health is the buyer's problem not the seller's problem, and only the sellers operate with a long planning horizon
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

  14. Back To Top    #14

    Join Date
    Jun 2013
    Location
    East TN
    Posts
    309

    Re: Why use tablets if they increase CYA?

    Sodium Hypochlorite is bleach and liquid chlorine from the pool store. Liquid chlorine is just a higher strength bleach. Sometimes the liquid chlorine can be bought cheaper than bleach.
    Here is a calculator for liquid chlorine that may be of help:
    http://poncatechsquad.com/Dan/Chlorine/
    18,000 Gallon Aboveground. Sand Filter with 2HP 2 speed Pump.

Posting Permissions

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