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Thread: New indoor pool chemistry

  1. Back To Top    #1

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    New indoor pool chemistry

    Hi all

    Got called this AM (early ) to go test a new hotel's indoor pool and give them a test and teach them 'pool school'.

    Well, I get there, test kit in hand, and the maint. guy has called in for the day . There is the GM and some woman with an accent who finally meet us to see the pool...

    Test results: (using Taylor 2005-K)
    cl = 0
    tc = 0
    pH = 8.0+ (five drops of acid demand = 7.4)
    TA = 150
    CH = 250
    cya = <30 some cloudiness but the dot is still there, from which I assume that it's ~< 20

    Dimensions are ~ 15 X 28' with 3 - 5' depth and corner, built in stairs. It's a marcite coated pool, unfortunately no one seems to know how long it's been since the plaster was applied and when it was filled

    Given my boss' 'follow-through', I may never see this pool again, but wanted y'all's take on the numbers.

    My take was to tell them to add 3 qts of 6% bleach and 2.5 qt muriatic acid (or 4.5lbs dry acid) and keep an eye on things til I get sent back -- I also told them to brush the pool daily. They have an auto chlorine feeder (pucks ) that they plan to replace with a SWCG at some point in the future. I warned them about the pucks and said that the SWCG would remove certain problems they are likely to encounter -- I did not, however, talk about chems to remove CC in an indoor pool

    Anyone care to help me with how to deal with this pool if I ever get called back, or have to help them via phone?

    Thanks, in advance, to all who respond
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

  2. Back To Top    #2
    JasonLion's Avatar
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    I calculate around 12,600 gallons (assuming 4 foot average depth).

    An indoor pool with a puck feeder???? They are out of their minds. They are probably already around the CYA level they want to have and will be well over in a few weeks. A puck feeder is nice to have for the first two weeks of fresh plaster startup and someone might have a well thought out plan to replace it with a SWG at the appropriate time, but it sure doesn't sound like anyone there is that organized.

    The first thing is to get the PH down and add some chlorine, just as you said. You are pushing the acid fairly hard. I calculate the PH as coming out right around 7.0 before the chlorine starts to get used up and going below 7 if the plaster doesn't push it up rather quickly. That might be for the best if they don't have someone in who knows what they are doing right away. For a homeowner that would be overdoing it. Assuming it is fresh plaster, the PH is going to keep going up rapidly for a while and they will need to check it and adjust with acid probably every day for at least a few weeks.

    Chlorine shouldn't have been zero with a puck feeder unless it was turned off or something is wrong. There might be algae, hard to say. They are going to need to start adding bleach regularly and find out if they can hold a chlorine level or not. The three quarts you suggested is enough to figure out if there is a problem or not, but only if there is reasonably rapid followup. If the chlorine is gone the next day then it will need to be shocked and if the chlorine holds then either the puck feeder is broken or they were on the edge of having an algae problem.

    Longer term the TA is going to need to be brought down. It isn't a problem right now, but the plaster curing will drive it up more. Plaster curing will also raise the CH, which shouldn't be a problem, particularly if the TA is brought down eventually.

    CC shouldn't be that large of an issue if they get the SWG. Without the SWG it will require attention. In any case it won't be a problem in the next several days. They have some immediate issues to work through before they worry about CC.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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  3. Back To Top    #3

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    Quote Originally Posted by JasonLion
    I calculate around 12,600 gallons (assuming 4 foot average depth).

    An indoor pool with a puck feeder???? They are out of their minds. They are probably already around the CYA level they want to have and will be well over in a few weeks. A puck feeder is nice to have for the first two weeks of fresh plaster startup and someone might have a well thought out plan to replace it with a SWG at the appropriate time, but it sure doesn't sound like anyone there is that organized.

    The first thing is to get the PH down and add some chlorine, just as you said. You are pushing the acid fairly hard. I calculate the PH as coming out right around 7.0 before the chlorine starts to get used up and going below 7 if the plaster doesn't push it up rather quickly. That might be for the best if they don't have someone in who knows what they are doing right away. For a homeowner that would be overdoing it. Assuming it is fresh plaster, the PH is going to keep going up rapidly for a while and they will need to check it and adjust with acid probably every day for at least a few weeks.

    Chlorine shouldn't have been zero with a puck feeder unless it was turned off or something is wrong. There might be algae, hard to say. They are going to need to start adding bleach regularly and find out if they can hold a chlorine level or not. The three quarts you suggested is enough to figure out if there is a problem or not, but only if there is reasonably rapid followup. If the chlorine is gone the next day then it will need to be shocked and if the chlorine holds then either the puck feeder is broken or they were on the edge of having an algae problem.

    Longer term the TA is going to need to be brought down. It isn't a problem right now, but the plaster curing will drive it up more. Plaster curing will also raise the CH, which shouldn't be a problem, particularly if the TA is brought down eventually.

    CC shouldn't be that large of an issue if they get the SWG. Without the SWG it will require attention. In any case it won't be a problem in the next several days. They have some immediate issues to work through before they worry about CC.
    Jason, thank you! - you were one of the folks I wanted to hear from I did the 'usual pool-guy route' and guessed that the pool was ~14,000 gal (I started to do the math and my partner said "14,000", which seemed close enough to me. I then ran the #s vs. the tables in my Taylor 2005-C booklet and 'fudged' the reduction on the tables 8). I thought about the '~overdosing of acid' but thought that a little more would do them better than a little under, as it's a new pool with (?) new plaster. You are correct that no one there seems to have a clue ! I almost left them my e-mail address and TFP address, but could not, given the fact that my boss sells chems -- I went out on a thin limb by telling them to get bleach out of the laundry room for an immediate fix.

    You and I both know better, but I'm constrained by the fact that I work for someone who has a pool store -- I try to be honest with the pool owners, but if I tell them the BBB - I stand a fair chance of loosing my job , because my boss wants the chem sales (it's not easy being a 'pool dude' who actually ~understands pool chemistry while having to give the 'party line' so that the pool store can $ell more chems ) Oh well, that's my cross to bare ...

    Thanks for your input
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

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