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Thread: CH Test Questions/ CH Rising

  1. #1
    Join Date
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    Default CH Test Questions/ CH Rising

    Hello everyone - been a while since I've been on the forum, it's nice to see familiar names are still here helping out. I've been maintaining my pool in the BBB style since we finished it 0 months ago and have been pleased. I got a bit complacent the past 3 months or so and didn't test/balance water as regularly as I should have. Several times the PH crept up +8.0 and chlorine got very low but I managed to bring it around. The water remained clear, no algea that I could see, etc.

    However, now the water is warming up (yes - here in Miami I think water temps below 88 are COLD!) my kids are using the pool and I'm back to testing/balancing regularly the past week. I think I have a problem with Calcium Hardness. First, some numbers from this evening 6 p.m:

    Cl 2.2 TC 2.2 Ph 7.6 Alk 80
    CYA >30 CH 525 Air Temp 80 Pool Temp 78

    Today I added some stabilizer to bring my CYA to 30-40 range. Then I'll bump up my CL numbers to 5-6. I ran the pool at these target numbers last summer and was happy with the results. My Alk ia consistently between 70 - 90. In November, my CYA was at 30 and my CH was 350 - last time I tested those two. Thought I could get away without testing those in the winter. Have added water a several times, couple of inches throughout the winter, no significant rain fall.

    Now my Ph creeps up constantly (newish pool!) and from day one I've had to add acid regularly to keep it at 7.6. I admit I haven't been consistent with maintenance this winter. I have had several instances where PH crept up too high(+8.0) before I caught it. In response I think Iadded too much acid all at once to bring it down to 7.4. The "bring Ph down gradually" rule was lost on me until now. Not sure if this contributed to the current problem.

    Now to my main problem with CH test/results (besides the incredibly high number).....

    1) when I add the 5 drops of R-0011L Calcium Indicator, my sample turns decidedly pink not red. Is that a problem?

    2) when adding the R-0012 Hardness Reagent, obviously my sample does not change from red to blue. Instead the pink color seems to "break up" into little particles floating in the water sample. I keep adding drops/swirling and eventually the water does begin to turn blue but the floating pink particles remain in suspension - reading at 525. What is happening/has happened?

    BTW, my fill water tests at 90 and there are no floating particles so I don't think the problem lies with the age/quality of the reagents, right?

    I know I need to drain and refill to lower CH but beyond that, these particles and what they represent have me worried....

    Also while the pool water looks clear to me overall, when I conduct the chlorine test it and the water turns from pink to clear, the water in the tube seems cloudy. Is this significant?

    And lastly - today I noticed a few brown stains on the walls of the spa, each a couple of inches in diameter, right by the steps. Are they part of all this?

    Sorry this is kind of long but I've tried to give a complete picture - can anyone help? thanks in advance.....

    Gracy
    Gracy
    16,725 gal gunite pool/1000 gal spa;exp agg finish; Jacuzzi 2 hp pump/Hayward cartridge filter/electric heater; Taylor K2006 Test Kit

  2. #2
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    waterbear is offline Lifetime Member Sniggle Mechanic waterbear 4 stars waterbear 4 stars waterbear 4 stars waterbear 4 stars
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    Default Re: CH Test Questions/ CH Rising

    Quote Originally Posted by Gracy101 View Post





    Now to my main problem with CH test/results (besides the incredibly high number).....

    1) when I add the 5 drops of R-0011L Calcium Indicator, my sample turns decidedly pink not red. Is that a problem?
    actually, it's supposed to turn pink
    2) when adding the R-0012 Hardness Reagent, obviously my sample does not change from red to blue. Instead the pink color seems to "break up" into little particles floating in the water sample. I keep adding drops/swirling and eventually the water does begin to turn blue but the floating pink particles remain in suspension - reading at 525. What is happening/has happened?
    This is often caused by metals in the water but it can also happen with no metal present but very high magnesium levels. It's a common interferance to the calcium hardness test. Nothing to worry about and easy to fix! Try adding 2-6 drops of the hardness reagent BEFORE adding the hardness indicator and then continue the test but count those drops added in your total. You should find that you get a definite end color without the interfenace. Here is the procedure:
    1) add the 20 drops of calcium buffer and swirl
    2) add 2-6 drops of hardness reagent (for this example let's say you added 6)
    3) add your 5 drops of indicator. The solution should be pink.
    4) Titrate with the hardness reagent until the color changes to blue. for this example let's say it took 28 drops.
    5) add the initial 6 drops and the 28 drops for a total of 34 drops which would be 340 ppm calcium hardness.

    BTW, my fill water tests at 90 and there are no floating particles so I don't think the problem lies with the age/quality of the reagents, right?

    I know I need to drain and refill to lower CH but beyond that, these particles and what they represent have me worried....

    Also while the pool water looks clear to me overall, when I conduct the chlorine test it and the water turns from pink to clear, the water in the tube seems cloudy. Is this significant?
    NO, this is also normal.
    And lastly - today I noticed a few brown stains on the walls of the spa, each a couple of inches in diameter, right by the steps. Are they part of all this?
    Could be iron stains, which would explain the interferance you are getting with the calcium test. Try holding a vitamin c tablet on them and see if they disappear. If they do they are iron. Easy to fix, just post your results and we can help.
    Sorry this is kind of long but I've tried to give a complete picture - can anyone help? thanks in advance.....

    Gracy
    Hope this is helpful.
    Retired pool store and commercial pool maintenance guy.

  3. #3
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    Default Re: CH Test Questions/ CH Rising

    Thank you for your quick response. Went out and did as suggested (11:30 am) - numbers are as follows:

    CL 6.0 TC 6.0 Ph 7.6 Alk 80
    Air Temp 82 Pool Temp 82

    CH 525 again - still had the floating particles in the end result. I want to say the change in color was more easily discernible but not really by much.
    As for the brown stains - the vitamin C took them away real quick.

    So - I'm not sure if I get this but it looks like:

    1) Brown stains are iron - which vitamin C will take away obviously. But can you only treat the individual spots or can you treat the pool in general to remove them and prevent them in the future? Why is it happening in the first place?

    2) The particles I see are caused by magnesium - which is related to my elevated calcium hardness levels. And the iron stains are also a byproduct of the CH? Any ideas why this is happening in the last few months...

    3) Do I need to test for metals then - how/where do you do that? Please, please don't say the pool store...yikes!

    I don't just want to fix it I want to know why it's happening so I can prevent it if possible. Thanks again.

    Gracy
    Last edited by Gracy101; 04-10-2007 at 12:32 PM. Reason: additional question
    Gracy
    16,725 gal gunite pool/1000 gal spa;exp agg finish; Jacuzzi 2 hp pump/Hayward cartridge filter/electric heater; Taylor K2006 Test Kit

  4. #4
    waterbear's Avatar
    waterbear is offline Lifetime Member Sniggle Mechanic waterbear 4 stars waterbear 4 stars waterbear 4 stars waterbear 4 stars
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    Default Re: CH Test Questions/ CH Rising

    Quote Originally Posted by Gracy101 View Post
    Thank you for your quick response. Went out and did as suggested (11:30 am) - numbers are as follows:

    CL 6.0 TC 6.0 Ph 7.6 Alk 80
    Air Temp 82 Pool Temp 82

    CH 525 again - still had the floating particles in the end result. I want to say the change in color was more easily discernible but not really by much.
    As for the brown stains - the vitamin C took them away real quick.

    So - I'm not sure if I get this but it looks like:

    1) Brown stains are iron - which vitamin C will take away obviously. But can you only treat the individual spots or can you treat the pool in general to remove them and prevent them in the future? Why is it happening in the first place?
    Iron can come into your water from several sources. Well water is a common one but it can also be in city water. To treat a whole pool you need ascorbic acid powder. Search the forum for ascorbic acid and you will find the complete procedure posted many times. Look for posts by Mbar. She is the forum's resident 'stain expert'!
    2) The particles I see are caused by magnesium - which is related to my elevated calcium hardness levels. And the iron stains are also a byproduct of the CH? Any ideas why this is happening in the last few months...
    The particles you are seeing is most likely caused by the iron in your water. Metals will cause this interferance in the test.
    3) Do I need to test for metals then - how/where do you do that? Please, please don't say the pool store...yikes!
    If you don't want to go to the pool store then you will have to invest in a test kit for iron. Taylor makes an excellent one.
    I don't just want to fix it I want to know why it's happening so I can prevent it if possible. Thanks again.
    Start reading the section of the forum called Stains & Metal Matters: Iron, Copper, Silver & More
    You will find a LOT of good info there!
    Gracy
    Hope this helps.
    Retired pool store and commercial pool maintenance guy.

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