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Thread: CYA at 110, drained 1/4 water refilled, now it's at 100 :-(

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    CYA at 110, drained 1/4 water refilled, now it's at 100 :-(

    I have been having trouble raising the FC level in my pool above 1.0 PPM.

    I replace my Rainbow 320 chlorinator thinking there was something wrong with it. The new unit dissolves the chlorine just fine, but the levels never rise.

    Warehouse Pool Supply (WPS) suggested testing the water and what we found on two different test over a three day period was this:

    Free Chlorine -- 0.4 ppm
    Total Chlorine -- 0.4 ppm
    Combined Chlorine -- 0.0 ppm
    pH -- 7.6
    Hardness -- 275 ppm
    Alkalinity -- 80 ppm
    CYA -- 110 ppm

    WPS stated that the CYA was "not bad", but could not tell me where all of my chlorine was going.

    So I jumped on the web, found this site and others, and discovered that a CYA of 110 is a problem, and is only fixable by changing the water. So I did what I thought for sure would work well. I dropped the level in the pool by 20", and refilled it. I took a photo of my water meter before and after, and this is equivalent to about 6500 gallons. I refilled the pool with tap water. (BTW, the tap water tests at 4.5 ppm and ZERO CYA)

    Went back to WPS, CYA is at 100, verified by my in-home test kit. I thoguht for sure a 1/4 change would make a bigger dent.

    So now what, more water change?
    Drain the pool completely and re-fill?
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  2. Back To Top    #2
    JasonLion's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    The common CYA test kits will measure any CYA level over 100 as 100, so there is no telling how high your CYA level really is.

    You should continue replacing water until you get CYA down to something more reasonable.
    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

    Strange way to lower CYA

    CYA is at 100; one of the guys at Warehouse Pool Supply said to fill my pool to it's highest level, then let it sit with no circulation for 12 hours.

    He said the CYA will rise to the top most part of the water. After the wait period, shut off the main drains, and drain the pool using ONLY the skimmers until they get to the point where the water is at the bottom of the skimmer intake, then refill pool to normal level.

    He said the CYA will get skimmed off of that top-most part of the water, and will significantly reduce the CYA levels.

    Is this total rubbish?

    Common-sense tells me that when you mix acid with water, it mixes and stays mixed.
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  4. Back To Top    #4

    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Thanks for the quick reply, Jason. I guess I can go for another 20 inch backwash.
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  5. Back To Top    #5
    Mod Squad woodyp's Avatar
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    Re: Strange way to lower CYA

    I nominate this as the first post in a new forum category on TFP............"Ya' Ain't Gonna Believe What The Pool Store Told Me!"

    All you're doing is changing out the percentage of water you added.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
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  6. Back To Top    #6

    Re: Strange way to lower CYA

    I thought it was BS.
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  7. Back To Top    #7
    bobodaclown's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    The other thing is to take a pool sample of water, dilute it with tap water, 50/50, then double the results. It should get you more in the ball park if the CYA excessively high.
    17K Kidney Shaped Pool Concrete (Diamond Bright) Pool, 3/4 hp 2 speed 115V Sta-rite Duraglas PEA5D-180L/P2R5D-181L (Impeller C105-92PS Diffuser C1-216P), 1.5 piping, Pentair CC100 Filter , Heat Siphon 100K BTU Heat Pump Pool Heater, Flow meter Blue White Flowmeter Model No. F-30150P, Hayward Astrolight SP0581N, SWCG CalimarTitanium Edition TE45 , Dolphin Nautilus Plus with CleverClean, Lakeland Florida

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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Quote Originally Posted by bobodaclown
    The other thing is to take a pool sample of water, dilute it with tap water, 50/50, then double the results. It should get you more in the ball park if the CYA excessively high.
    Great idea! I just did that... came up with a CYA 60. So I guess I am really at about 120!? So if that's where I really am at NOW (even after the 20" drainage of water), then if I dump half the pool water at this point, I'll be at 60, yes?

    What do all of you think about being at a CYA of 60 in Houston TX in the summer time?
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  9. Back To Top    #9
    Mod Squad woodyp's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Anywhere from 40 to 60 is doable in good old Texas sun. Mine is at 40 and fixing to head to 50ish.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  10. Back To Top    #10
    Butterfly's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    You can do 60 in Houston. Don't use the chlorinator, tho

    ETA: woody sure is fast today
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  11. Back To Top    #11
    Mod Squad woodyp's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Woody is headed to his own pool for the balance of Fathers Day. Over and Out!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  12. Back To Top    #12

    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Quote Originally Posted by Butterfly
    You can do 60 in Houston. Don't use the chlorinator, tho

    ETA: woody sure is fast today
    OK, so what do I use to chlorinate the pool? Doesn't anyone make an unstabilized chlorine puck?
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  13. Back To Top    #13

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    duraleigh's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    OK, so what do I use to chlorinate the pool? Doesn't anyone make an unstabilized chlorine puck?
    Use Bleach. No, no such thing as unstabilized pucks or powder....can't be done.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  14. Back To Top    #14

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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    ahhhh, yes! Welcome to the world of buying bleach in bulk! LOL. Its not as bad as it seems, I get quite the workout. I don't buy bleach from Walmart or the like. Chlorine is the ONLY reason I go to the pool store anymore...I just can't physically carry that many bleach bottles! I pay a little more, but the pool store chlorine is 10% and I only get it when its buy 2 get one free and on double stamp weds! LOL! But liquid chlorine is the only way to go!!!

    You definitely NEED to lower CYA...I'm here in sunny south florida and I maintain my pool at 40 ppm CYA and my pool is unscreened with at least 10 hours of sun ALL FLIPPIN DAY! I need to watch my CL levels a little closer than most, but I've learned to appreciate the work of more effective chlorine with all of my landscaping, pollen, and swimming dogs.
    When I first bought the house (1st time pool owner) I was pool stored and bought the pucks and was putting 4 pucks a week in the floaty duck. After awhile, I couldn't figure out WHY I couldn't fight off the algae?? DUH! Everyone on this board really helped me out.
    I bit the bullet, did a 1/2 drain to get a jumpstart on the ridiculous CYA levels of over 150! Then I let rain and regular vacuuming to waste bring me back into normalcy.
    You'll find a CYA level that works best for you and your situation once your levels drop...it just takes a little experimentation.
    Keep referring to this website and you'll be back on track!!!
    32x16 -16,500 gallon plaster pool with connected spa and spillover, Hayward RS 1 HP pump, 2 Hayward Cartridge filters. 10 hours of direct sun a day and a first time pool owner!!

  15. Back To Top    #15

    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Quote Originally Posted by duraleigh
    OK, so what do I use to chlorinate the pool? Doesn't anyone make an unstabilized chlorine puck?
    Use Bleach. No, no such thing as unstabilized pucks or powder....can't be done.
    OK, so I keep the CYA levels low (btwn 40 and 60), then how MUCH bleach? Where to buy? Will need a pallet from Sam's club? Should I buy a 55 gallon drum? Is the off-brand the same strength as Clorox? ( I guess I could read the label on that one.

    If the CYA levels drop too much, then use the pucks for a while?
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  16. Back To Top    #16

    Join Date
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    That's where the pool calculator comes in....enter all your #s...it will then give you the ppm of CL you need to shock. Then go back to the top of the calculator, enter that shock value into the goal for Cl and it will tell you how much to add. The main page of this website has a link to the calculator. BOOKMARK IT!
    You can buy the chlorine anywhere...just make sure you get regular bleach, not the scented kind or the new thick stuff meant for outdoor cleaning. Typically, the bleach you can buy in the stores is 6%. Walmart is generally the cheapest...but if you belong to a "club" check out the prices there. Generic brands are fine as long as you know the stock is turned over often and you're not buying old (and less potent) bleach. And yes, buy alot initially. Especially if you need to shock...it's better to have it on hand than have to run to the store every other day!
    I keep pucks in case I go out of town for a few days...another reason to keep a lower CYA if you can. I don't worry about using them when I have to and shocking the pool is easier with a lower CYA after the crazy rainstorms we have down here.
    Good luck and happy hauling!
    32x16 -16,500 gallon plaster pool with connected spa and spillover, Hayward RS 1 HP pump, 2 Hayward Cartridge filters. 10 hours of direct sun a day and a first time pool owner!!

  17. Back To Top    #17

    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Quote Originally Posted by csigirl
    That's where the pool calculator comes in....enter all your #s...it will then give you the ppm of CL you need to shock. Then go back to the top of the calculator, enter that shock value into the goal for Cl and it will tell you how much to add. The main page of this website has a link to the calculator. BOOKMARK IT!
    That calculator kicks ***!! Thanks! I wish they "had an app for that"!
    Houston, TX
    26,000 gallons, built May of 2009
    In ground Pebble Sheen finish
    Pentaire Intelliflo VS3050 runs from 8am to 11pm at 900 RPM with a burst to 3450 for two hours in the morning, again at 2pm, then again at 8pm.
    Pentaire FNSP60 DE Filter
    Pentaire MasterTemp 400 Heater
    Pentaire Legend cleaner with booster pump
    Rainbow 320 Chlorinator

  18. Back To Top    #18

    Join Date
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    If you have an iPhone...I think it IS an app. Not sure since I have an Android, but I've heard rumors....
    32x16 -16,500 gallon plaster pool with connected spa and spillover, Hayward RS 1 HP pump, 2 Hayward Cartridge filters. 10 hours of direct sun a day and a first time pool owner!!

  19. Back To Top    #19
    JasonLion's Avatar
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    Re: CYA at 110, drained 1/4 water refilled, now it's at 100

    Quote Originally Posted by csigirl
    I think it IS an app.
    Indeed. Pool Calculator for iPhone App Store link.
    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

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