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Thread: Incredibly High Bather Load

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    Incredibly High Bather Load

    I have an indoor pool that I'd like to convert to salt. We teach swim lessons to little kids, so having something a little softer on the skin is a big plus. Currently the pool is kept at 90 degrees. We have about 100 people per day using the pool. Although, that number is likely to reach into the 200's sometime in the next few years. And we are open for business 7 days a week. I'm not looking to be frugal here, I will spend the money if the product is worth it. And I would like it to be fairly easy to control as many employees have to be trained how to use it. So.... Suggestions?
    Indoor
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    Mod Squad Bama Rambler's Avatar
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    Re: Incredibly High Bather Load

    Welcome to TFP.

    Wow! That's a lot of bather load. Especially since they're lots of little kids.

    How are you sanitizing it now?
    Does the pool have any supplemental sanitation such as UV or ozone?

    Any of the major brands will have something that should work for you.
    Dave J. TFP Moderator
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    Re: Incredibly High Bather Load

    My PB installed a tab feeder when it was built. It's AWFUL! He also put it before the heater, which has caused me to burn through a pool heater a year. Ugh. There is no supplemental sanitization going on.
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    Mod Squad Bama Rambler's Avatar
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    Re: Incredibly High Bather Load

    Where are you located?
    Does your locality allow swcg's for a commercial pool?

    Send Josh at saltpoolguys a PM. He can probably give you some guidance in your quest.
    Dave J. TFP Moderator
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    Re: Incredibly High Bather Load

    we have SWGs for commercial pools like that, but it will highly depend on whether NSF approval is required in your locality for commercial pools

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    Re: Incredibly High Bather Load

    100 to 200 people in a 26,700 Gallon pool indoor pool at 90 degrees and lots of kids? I think that you're going to need something more than chlorine. Ozone might be a good choice.

    Note: Ozone cannot just be pumped into the return line. It has to be done properly, which means contact tanks, offgassing and ozone removal etc.

    Are you currently having issues with chloramines?

    http://findarticles.com/p/articles/mi_m ... _15602969/

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    Re: Incredibly High Bather Load

    It is a little too late now, but whoever designed the pool for this type of bather load should have suggested an outdoor contact/holding/treatment tank of a very large capacity to buffer the bather load, provide outdoor UV exposure and function as a contact tank for outdoor ozone treatment if needed.

    For your current situation, sure you could add ozone, but as the previous poster mentioned it has to be done properly and that much ozone has to be monitored when you have small children in an indoor environment. Ozone is an airway irritant and linked to asthma in small children. Residential ozone units would be inadequate for this task and therefore don't pose as much of an air quality contamination problem. Commercial units require all the stuff mentioned above and are around $20k for a setup.

    Let us know what you find that works......

    What do you do when a child has an accident in the pool? Do you close it and shut down for several hours? Would that affect your business negatively?
    IG 24k plaster with overflow spa. Goldline PS-8 SWG. Tristar 0.75 HP filter pump, Polaris 280, large cartridge filter, 400k BTU NG Max-E-Therm HD, SR Smith Turbo Twister, Life Saver pool fence, ORP managed.

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    JasonLion's Avatar
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    Re: Incredibly High Bather Load

    I would look into UV and ultra high turnover rates.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Incredibly High Bather Load

    Quote Originally Posted by learthur
    For your current situation, sure you could add ozone, but as the previous poster mentioned it has to be done properly and that much ozone has to be monitored when you have small children in an indoor environment. Ozone is an airway irritant and linked to asthma in small children.
    Ideally, after the ozone is off gassed, it would be passed through a GAC filter to remove any remaining ozone in the water. Monitoring the air in the room for ozone would be necessary to ensure that no significant levels of ozone were returning to the swimming environment.

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    Re: Incredibly High Bather Load

    Are you open 24/7? How is it possible to teach that many kids a day how to swim? Even a typical YMCA can't handle that many kids a day for their swim classes.

    WOW.
    24' x 52" AGP = 13.5k gallons
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    Re: Incredibly High Bather Load

    Tablets with that kind of load will not be pretty. You'll replace water due to CYA level increases frequently.

    What side is the plumbing and filter?

    IMHO, you will need a good UV system and a large cell, on designed for a 60K gallon pool or a liquid feeder and ORP system, serious ventilation system, and limits on your bather load. Ozone will create issues you don't really want.

    Don't even think about 200/day. Thats ***** not common sense talking. This pool is too small for that load. You are already at it's limit. Editied for politeness. JasonLion

    Reduce the pool temp to no more than 84. You'll overheat the kids at 90.

    I strongly urge you get a consult with someone that has a large commercial facility under their care. Its a totally different world than residential pool care with a lot more at stake.
    Owner of - PoolGuyNJ LLC
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    Re: Incredibly High Bather Load

    Quote Originally Posted by PoolGuyNJ
    Ozone will create issues you don't really want.
    Can you elaborate on the issues ozone would create?

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    Re: Incredibly High Bather Load

    The two opposing issues with ozone are that if you have too little it doesn't do much, while if you have enough for a public pool it is tricky to keep it out of the air. Ozone in the air is a respiratory irritant. Even at low levels it can be very problematic for people with respiratory problems or people with constant exposure. There are various ways to setup special plumbing to keep the ozone where you want it, and ventilation systems to get any excess ozone out of the room, but those systems require attention and maintenance. If something goes wrong you have to turn the ozone off or you get complaints from the swimmers, and in a commercial pool risk legal liability. But turning the ozone off means the water isn't going to stay clean.

    UV is more reliable. Essentially all that tends to go wrong is that the bulbs blow out. If you keep a couple of spare bulbs on hand you have a quick and easy fix.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Incredibly High Bather Load

    Interestingly, this article by Wojtowicz says that ozone doesn't react quickly with urea and is even slow with ammonia at pool/spa pH since most of the ammonia is ammonium ion. Nevertheless, we've seen chlorine demand get cut in half in residential spas with ozonators so clearly something is going on there and I presumed that it was oxidation of urea since that was the largest nitrogenous component of sweat and urine and since the total chlorine demand was consistent with that predicted from the nitrogen content of sweat and urine. Also, chlorine alone does seem to handle bather waste within 24 hours if the active chlorine level is reasonable (4 ppm FC with 30 ppm CYA or so) and the water temperature is hot. The chlorine and possibly ozone oxidation of urea may be very temperature dependent, though Blatchley's experiments (in this paper) didn't show more than the usual sort of temperature dependence. Of course, the only way to know for sure about urea is to measure in such spas, but there isn't an inexpensive test kit for that so this hasn't been done.

    As for UV systems, by themselves UV doesn't oxidize many compounds directly such as urea, but just like UV in sunlight it can break down chlorine (both hypochlorous acid and hypochlorite ion) creating hydroxyl and chlorine free radicals. It is these free radicals that do most of the work of oxidation of organic compounds, probably including urea. Medium-pressure UV (as opposed to low-pressure UV) with its broader spectrum would break down more chlorine resulting in more free radicals. Though this increases chlorine usage, it is a small increase compared to that from high bather load so there could be a net reduction in overall chlorine demand if the UV can oxidize urea instead of chlorine having to do so.
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    Re: Incredibly High Bather Load

    Wow. First of all, thanks for all of the responses. I don't know who to thank or respond to first!

    After talking to a lot of other people who run pools similarly to mine, I decided that salt was not for me. In fact, I know of a $25,000 Autopilot, and at $35,000 TMI that people are looking to unload cheaply. They took them off of their pools and the units are now gathering dust in their garages.

    It seems as if JasonLion is more in line with the other feedback that I'm getting. Everyone seems to love UV. And perhaps some faster/better turn over. So, I've decided to put a simple liquid chlorine/acid feeder on the pool. Right now I'm leaning towards the Hayward Cat 2000. I will see how that affects the pool, and then move on to turnover/filtration.

    As to the bather load, I have seen people run 2000 kids a week in a smaller pool. It can be done, and at that temperature. Those things are not negotiable. Having said that, I greatly appreciate any help in managing this pool! It is sure to be a steep learning curve for me.
    Indoor
    26,700 Gallons
    Plaster
    Sand Filter
    2 HP pump

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    Re: Incredibly High Bather Load

    When dissolved in water, ozone can react with water contaminants by two mechanisms: by direct reaction as the O3 molecule, and by indirect (hydroxyl) free radical reactions. In strongly acid solutions, the direct reaction predominates, but above pH 7 radical reactions predominate in addition to direct reactions.
    :
    Reactions of Ozone With Monochloramine:
    Haag and Hoigné (1984) also have shown that ozone slowly oxidizes monochloramine to produce nitrate and chloride ions according to the following equation:

    NH2Cl +3O3 --> NO3- + Cl- +3O2


    http://jspsi.poolhelp.com/ARTICLES/JSPS ... p25-44.pdf
    Ozone Destruction of Chloramines
    • Ozone breaks down Chloramines by oxidation in two ways
    – By breaking down the N-Cl bonds of the Chloramine molecules through oxidation by
    ozone (this process occurs at the point of ozone injection and continues the oxidation
    process as it passes at low levels into the pool)
    – Ozone also forms hydroxyl radicals, adding to the Chloramine oxidation process
    • Ozone reduction of Chloramines is known to reach zero
    UV Destruction of Chloramines
    • UV can break down Chloramines in two ways
    – By breaking the N-Cl bonds of the Chloramine molecules with UV light energy (this
    process occurs in the UV chamber only)
    – By forming small numbers of hydroxyl radicals with UV light energy, which oxidize
    Chloramines (this process occurs within nanoseconds, effectively occurring only in, or
    very near the UV chamber)
    • UV reduction of Chloramines has been documented to reach near zero.

    http://www.icwt.net/conference/WaterSup ... 0Hamil.pdf
    Since most of the ammonia will be in the form of chloramine, the ozone will oxidize it. And, since the hydroxyl radical will be produced, and it will oxidize ammonia or chloramine, ozone can be effective.

    Using ozone and UV together creates an Advanced Oxidation Process.

    In the UV ozone process, photons in the UV spectrum convert ozone in the presence of water to oxygen and peroxide. The peroxide then reacts with the ozone to form the hydroxyl radical. A simplified reaction sequence is shown below:

    O3 + H2O → O2 + H2O2 (in the presence of UV light)

    2 O3 + H2O2 → 2 •OH + 3 O2

    Organic oxidation occurs due to the reaction with hydroxyl radicals, molecular ozone and direct photolysis.

    http://www.spartanwatertreatment.com/ad ... Ozone.html
    UV might be a better choice than ozone due to the possible issues with ozone.

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    Re: Incredibly High Bather Load

    "After talking to a lot of other people who run pools similarly to mine, I decided that salt was not for me. In fact, I know of a $25,000 Autopilot, and at $35,000 TMI that people are looking to unload cheaply. They took them off of their pools and the units are now gathering dust in their garages."

    Hello Martha,

    I would be interested in finding out more about the AutoPilot commercial system that has been removed from a facility. Can you PM me the information? It would help me understand if I have a dealer that needs training, or if I need to contact the facility.
    Sean Assam - Sean@teamhorner.com
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    Re: Incredibly High Bather Load

    Thanks James, for that additional link. In particular regarding urea it also states the following:

    Most organic compounds, particularly those which are refractory in nature (i.e., organo–nitrogen compounds – urea, creatinine; organo–chlorine compounds – chloroisocyanurates, trihalomethanes), are only slightly reactive with ozone, and are not destroyed by ozonation, except upon greatly extended reaction times (up to hours), which are not practical in pool and spa water treatment.
    and also this:

    On the other hand, when the amino acids and urea are treated with chlorine, the corresponding N– chloro–derivatives are produced. In turn, the N–chloro compounds are much more susceptible to ozone oxidation than are the non–chlorinated nitrogen–containing compounds. Consequently, the presence of free residual chlorine (or bromine) in the pool/spa basin will form N–halo–derivatives which are easier to oxidize with ozone.
    So it does appear that ozone may be of some benefit along with chlorine once urea gets chlorinated. So between that and the hydroxyl free radical formation, ozone may be of benefit though with challenges that UV does not have.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    Re: Incredibly High Bather Load

    Quote Originally Posted by Martha
    After talking to a lot of other people who run pools similarly to mine, I decided that salt was not for me. In fact, I know of a $25,000 Autopilot, and at $35,000 TMI that people are looking to unload cheaply. They took them off of their pools and the units are now gathering dust in their garages.
    curious to find out why they uninstalled the units? would you be able to elaborate a bit more on the problems they have found with using SWG?

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