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Thread: Waiting for Test Kit, FC at 0

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    Waiting for Test Kit, FC at 0

    Right now the water is almost clear, but I'm concerned about leaving it at 0 FC for a few more days while I wait for the test kit that I'm about to order. Do I need to add anything while waiting besides tablets?
    My inground, concrete, 35 year old pool holds 32,000 gallons and has a sand filter. We live in Texas, and keep the water temperature in the 80's with a solar cover. I've had good success with pool store chemicals until this year. We had unusual rain, and it took a while to get balanced. Now, I keep shocking the pool, which raises the FC for about 2 days, then it goes to 0 on my test strips, despite using chlorine tablets. The pool store says everything looks good, just shock it and it will be fine. Right now the water is almost clear, but I'm concerned about leaving it at 0 FC for a few more days while I wait for the test kit that I'm about to order. Is this a problem?
    Also, can I really buy the large quantity of bleach that I will need at the store?

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    Re: Waiting for Test Kit, FC at 0

    Welcome! FC at zero is bad. Using tablets is bad if you don't understand their effects and future consequences.

    Test strips are bad and which test kit are you buying? I hope it is a drop test that includes FAS-DPD chlorine test. (Taylor k2006 or tf-50 or tf-100

    What are you using to shock it? Liquid or bags of powder? You can buy as much bleach from the store as they carry on the shelf or that you can carry in your cart. Have never heard of anyone being stopped.

    So what is a suggestion for what you should do...Do you have the yellow color matching OTO drop test?

    Stop using pucks or granular chlorine until you get your test kit.
    Not sure what the proper thing to do with only having test strips and no CYA reading but you need to get and keep chlorine in your pool before it gets worse than it is. Without knowing what size bottles and what strength chlorine/bleach your going to buy I can't say anything for sure....but a common strength and size is 121 oz bottle of 8.25% bleach...I would add some right away (2 jugs), like now to get some chlorine in there, and then add 3 jugs every night at sun down and get your test kit ordered asap.

    We shall see if others agree of if they have alternate suggestions.
    12500 gallons, 24 foot round above ground
    Hayward Sand filter, Pentair OptiFlo 1HP 2-Speed pump

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    Re: Waiting for Test Kit, FC at 0

    Thanks, so much. I have no drop tests now, but should receive the TFTest 100 middle of next week.

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    Re: Waiting for Test Kit, FC at 0

    You can get by with one large jug of chlorine each evening until you get a kit. Use the solar cover to help you keep the sun from destroying the FC. The important thing to keep in mind is no real solid advice can get to you until we have a solid starting point. That starting point begins with test results from a dependable kit that we have confidence in.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Waiting for Test Kit, FC at 0

    Test Kit Results:
    FC=.5
    CC=.5
    CH=800
    TA=270
    CYA=100
    I was using tablets and powder shock from a pool store until recently. I see I have some problems here. In our area dumping pool water is not feasible since we have water use restrictions. Any good advice would be appreciated. I have been adding chlorine each nite as suggested above.

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    bridgman's Avatar
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    Re: Waiting for Test Kit, FC at 0

    Your CYA might actually be higher than 100 -- might be a good idea to re-test following point 9 in the extended CYA test directions :

    http://www.troublefreepool.com/threa...l=1#post203524

    You're basically diluting the pool water 1:1 with tap water before testing then doubling the result, which lets you measure up to 200 ppm.
    Cedar hot tub, 680 US gallons - Snorkel wood-burning heater, canoe paddle, "offline" Intex 1000 GPH pump/filter with skimmer

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    Re: Waiting for Test Kit, FC at 0

    You're right, the cya is 200

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    Re: Waiting for Test Kit, FC at 0

    You're not going to like this, but... if it reads 200 when you dilute it 1:1, it wouldn't hurt to do one more test (sorry) but diluting 1:1 twice then multiplying the result by 4. So...

    Fill up to 7ml mark with pool water
    Top up to 14ml mark with tap water
    Pour half out so you're back down to 7ml mark
    Top up to 14ml mark with tap water
    Pour half out so you're back down to 7ml mark
    Add the reagent, test, and multiply result by 4.

    I've seen CYA numbers up in the 300's already, and I'm new here...
    Cedar hot tub, 680 US gallons - Snorkel wood-burning heater, canoe paddle, "offline" Intex 1000 GPH pump/filter with skimmer

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    bridgman's Avatar
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    Re: Waiting for Test Kit, FC at 0

    BTW unless there is some option for draining/refilling or Reverse Osmosis treatment in the very short term I think you need to start adding a lot of chlorine as well. Since the CYA level is so high you're going to need more than usual.

    I plugged 32000 gallons and a CYA level of 200 into PoolMath -- recommended FC range is 15-23 ppm. Going from zero to 23 ppm is just under 9 gallons of 8.25% bleach. Unless someone has a better idea, I would start with something like that.

    Go ahead and set PoolMath up for your pool -- you'll need to :

    - enter volume in gallons at the top
    - enter CYA level a few rows down under "Now"
    - go to Suggested Goal Levels at the bottom of the table, pick TroubleFreePool, bleach, <not sure what surface to pick for a concrete pool, would that be plaster ?)

    At that point you can go back up to FC near the top, enter Now and Target levels, enter bleach concentration and jug size. You'll get an answer like 1110 oz but when you point at it with the cursor a field above it will show number of gallons/jugs.

    BTW if the double-diluted test shows that your CYA is actually higher than 200, enter the higher number into PoolMath instead.
    Cedar hot tub, 680 US gallons - Snorkel wood-burning heater, canoe paddle, "offline" Intex 1000 GPH pump/filter with skimmer

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    Re: Waiting for Test Kit, FC at 0

    The cya is 240. Looks like I need to add 1055 oz. of 10% cholrine. I'll do that this evening.

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    Re: Waiting for Test Kit, FC at 0

    We did a backwash and added some water, so I did several tests today.
    After adding the 8 1/4 gallons of chlorine, the chlorine was 25. It probably wasn't all mixed; this morning it was 6ppm. This afternoon it is 4ppm.
    CYA is 208, and pH is 7.8. I think the improvement in cya may be partly due to added water, my improving skills, and today's strong sunlight for reading the test; perhaps 240 was a little high.

    The water looks clear. There was a little algae growing in the corners, so I brushed it and used the Aquabot yesterday. After the chlorine last night, it looks good.

    Now what?

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    bridgman's Avatar
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    Re: Waiting for Test Kit, FC at 0

    Basically keep adding chlorine so that FC never gets below 15. Each time you add, add enough to raise from <wherever you are> to 23.

    I guess you'll have to drop pH below 10 every so often in order to get accurate test results, don't think the test works well at higher FCs.

    Do the water restrictions get relaxed at some point during the year ? If so then start planning now so the day the restrictions get relaxed you're ready to start partial drain/refill cycles. There's not a lot of precedent for running successfully at such high CYA levels... main thing is to keep FC high enough that an algae bloom doesn't have a chance to get started because if it does you would need an insanely high FC level to stop it.
    Cedar hot tub, 680 US gallons - Snorkel wood-burning heater, canoe paddle, "offline" Intex 1000 GPH pump/filter with skimmer

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    Re: Waiting for Test Kit, FC at 0

    Thanks for the advice that I have not been able to follow yet, due to current time constraints, and a hesitancy to want to add 8 gal of bleach every day. I purchased 18 gallons today, and used 3 in hopes of raising the FC to 8. My pool still looks clear and beautiful. Perhaps this is because I have been still using algicide. It seems that the pool eats chlorine. By morning it's lower than I expect from pool math, (and lower than at night after the addition, but I don't know if my water is well-mixed for those night-time readings).

    My question concerns cleaning the stairs which are built into the wall, and broken in several places, providing a very uncirculated place. I never thought about this until I was reading another thread. I think I'll shoot some bleach in there, wait a few hours, spray it out with a hose, then run the Aquabot. Any other suggestions?

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    Re: Waiting for Test Kit, FC at 0

    Do you mind adding your signature? It speeds up the process by letting everyone know your pool details. Here is what we need: http://www.troublefreepool.com/conte...etting-started

    You mention that you aren't sure of you results because the water might not be mixed well for your night time readings. Why do you suspect that the water is not mixed well? You should be running your pump 24/7 while doing a SLAM.

    SLAMing a pool means bringing the pool to shock level for your CYA level and "Maintaining" it. Adding bleach once a day allows the algae to reproduce faster than you are adding chlorine. http://www.troublefreepool.com/conte...tain-shockingl

    Hopefully, you will be able to clean up behind your stairs and that will help with your chlorine demand. However, I suspect you have a lot of other organics to kill which will require a lot of bleach based on your CYA and water restrictions. While you will need large amounts of bleach at first, once you kill off algae, it take less and less chlorine over time. However, I would suggest you test and add bleach hourly at the beginning and less frequently as you are able to hold FC.
    Karen
    33K IG w spa plaster, Pentair 1HP Whisperflo, DE Filter, SWG CircuPool RJ-60, Dolphin Triton Plus, Raypak Dig 336K BTU, TF-100.
    Pool Math Chlorine / CYA Chart SLAM - Shock Level And Maintain
    2017 replaster/retile

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    Re: Waiting for Test Kit, FC at 0

    Success! FC has been between 17.5 and 27 for a week and my bleach use has gone from 4.7 jugs six days ago to no jugs needed today. It's really true; the sanitizing level for my pool is 17-25 ppm because of the high CYA. It does not seem harsh, nor does the bleach smell particularly strong. I thought the water was clear before, but it is much better now.

    2 questions:
    How does the CYA cause this?
    What is the next step? CH was 800, TA was 270, pH shows 7.5 (but I'm told this is unreliable at high FC level) More minerals are attaching to the tile above the water level (is that scale?)
    32K gal, 30 y.o. painted concrete pool with Hayward sand filter and 1 HP single speed pump. TF 100 test kit. Polaris and Aquabot.

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