Pool water tests fine, but causes more than the normal degree of eye irritation, and also really dries my skin. Any ideas why?
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Pool water tests fine, but causes more than the normal degree of eye irritation, and also really dries my skin. Any ideas why?
Hello and welcome to the forum! We'll need more information to be able to help. What type of pool, and volume, type of filter, size of pump and a current set of water testing results taken with a drops-based kit. Also, tell us exactly what all you have put in the pool meaning ingredients, not just "shock." Then somebody here can try and help.
Thanks Mom. 100k gallon pool, plaster, indoor, heated to 86-88 deg year-round, remodeled about 1 year ago, liquid chlorine (no salt), sand filters, pH 7.2-7.6, TA 100, Calcium 250, FC 2-5 ppm, old test kit with a Taylor K-2006 on the way. My old kit does not detect any combined chlorine, but I do not trust it. I have searched the forums some and noticed that a low TDS = osmotic pressure on the eye. I guess that my TDS is probably low since the water was new about a year ago. Can I just add salt to a chlorine pool without changing anything else? Thanks again,
Mike
Mike,
Big pool such as this and especially since it is an indoor pool are a little different than residential pools. I'm going to ask Ben to take a look at your thread and get his take on things. Sit tight for now.
Hi Mike;
As Janet said, indoor pools are different than outdoor pools, and commercial pools are different than residential pools: indoor, commercial pools are REALLY different.
The good news is, I have some extensive experience with pools like yours. The bad news is, I have more experiential answers, than I do scientific ones. I found some things that seemed to work, but I can only guess why. If there is reliable info on what happens in a hot commercial indoor pool like yours, I haven't found it.
The problem is worse on hot pools, like yours, than on colder ones.
In general, the effects you describe are from chlorinated organics. In the potable water business, they are often called DBPs or Disinfection By-Products. You'll also seem them referred to as THMs -- Tri-Halo-Methanes, although that is a narrower term.
First, let me tell what I found does NOT work:
#1 - 'Shocking' or breakpoint chlorination.
If the organics were simple ammonia, that would work, but they are not. As a result, 'shocking' can actually make the problem worse.
#2 - Non-chlorine shocks
I found ZERO improvement, at any level of use. When I tested the, I was able to buy 'Oxone' cheaply in 50# (I think maybe they were 20Kg) bags, so I tested higher levels than recommended, as well as recommended levels. Using monopersulfate totally screws up ORP based control and DPD testing, but I found no improvement whatever in water quality.
#3 - Clarifiers
No effect, even though I was using a sand filter.
Second, there was one thing that I found absolutely and dramatically DID work: contaminant source control!
#1 - On one pool, I got a HUGE improvement by persuading the toddler-swim class teacher to shorten classes from 1 hour to 45 minutes, and require that moms put their toddlers on the potty before swimming, "whether they thought they had to go, or not". This step had the single greatest effect of anything I ever did!
#2 - Placing signs in the pool and women's locker room begging and pleading and threatening women to refrain from using lotion before entering the pool, and asking them to PLEASE wash it off, if they already had it on.
In general, you want to understand your contaminant sources:
+ USS competitive swimmers (ie, 2 hour practice swimmers) ALL pee in pools. I am NOT kidding or exaggerating about this. I absolutely do know. Anything to reduce this helps. Coaches hate it, but a mandatory hourly 'potty' break can work wonders. Of course, the coaches then have to chase all their slackers out of the bathroom after, so it becomes an ongoing effort to maintain the required break.
+ Babies and toddlers pee in pools, and babies poop in pools. Swim diapers do NOTHING to help with this. What makes a swim diaper is simply that they don't 'blow up' and clog the filter. There's nothing you can do about the babies, except keep them out of the pool. But the toddlers can be managed per above.
+ Older women in water aerobics may be the worst. (My wife was a water aerobics instructor for years, so I'm not guessing here.) They often wear too much lotion, too much perfume (it often lies in an absolutely choking layer 2" above the water*) and have leaky bladders (my wife would overhear them discussing their problems, in the locker room). A mandatory shower first policy + signs will help. With this population, they tend to be enforcers: (I had to do so, so you do too!). Explaining that THEIR discomfort results from their fellow swimmers body lotion or full bladder can work wonders, because they will say to each other what you can't.
+ Lowering water temperature will help too, because doing so reduced skin-drying effects AND sweating.
+ In general, encouraging showers helps a LOT because most people will pee when they shower, so you kills two birds with one stone, so to speak. Also, making sure NO class runs over 1 hours without a break helps.
+ But, you also need to OBSERVE your pool. There may be unexpected sources of contamination there, say a PT class that FOLLOWS a massage therapy session. In general, you are looking to reduce all of the following:
-- urine, feces, spit
-- sweat !
-- lotion, body oil, suntan lotion
-- hair conditioner
-- perfume
+ There is another class of problem contaminants I should mention, even though you indicated you did not use them:
-- algaecides
-- enzymes (see below)
-- defoamers
-- pH stabilizers (beside borax)
-- non-chlorine shocks (some can cause SEVERE problems!)
-- bromine tabs (hydantoin build up can cause serious problems, too)
-- hodge-podge pool chemicals -- use ONLY single ingredient products !!!! This is very important.
Third, there are some operational improvements that will help.
+ Improved aeration. (TO BE EXPANDED)
+ Improved ventilation (TO BE EXPANDED)
+ Lowered water temps (TO BE EXPANDED)
+ Chlorination consistency (TO BE EXPANDED)
+ Higher pH (TO BE EXPANDED)
+ Improved filtration (TO BE EXPANDED)
+ Enhanced filtration (TO BE EXPANDED => contaminant adsorption)
+ Improved operational stability (TO BE EXPANDED)
+ Regular water replacement plan (TO BE EXPANDED)
Finally, AFTER you've done everything above, it might be worthwhile to
+ test the use of enzymes (TO BE EXPANDED)
+ consider the use of UV irradiation (TO BE EXPANDED)
+ (last resort) adopt a European type ozonation / de-ozonation process with post chlorination
==> It's going to take awhile to finish this thread <==
Ben
* Funny story: one lady who frequented my wife's pool during the open swim period when my son and I (the one in this thread: Chattanooga Rat Race, minus about 18 years) apparently applied cheap perfume with lawn sprayer. Trying to swim laps, when she got in, choked me and triggered my son's asthma. But we worked out a solution. Like many of the women in her set, she did not want to get their hair wet . . . at ALL! So I'd have my son practice his butterfly stroke or do fast kick sets, every other lap. She got out, and complained to the manager -- with whom I'd already cleared my plan. (This lady was a complainer, and an irritant to other patrons as well.) The manager, struggling to keep a straight face, explained that it was an open swim period, and that the club really couldn't guarantee pool users would be able to keep their hair dry. She flounced off to the locker room in a manner possible only for overweight 65 year old women, hmphing all the way, as the staff collapsed into silent giggles.
Wow! What a great reply and tons of information. I do only use a handful of chemicals: NaClO, baking soda, HCL, and calcium, but I have only been employed here for about 7 months. Some time before me, there were several different people adding chemicals to the pool, and they ended up with a high CL level that was bleaching out the indicator, so they though it was 0 CL and continued to add CL. One of their water samples tested at 55ppm CL! So they added Chlor-out, and I am not sure what else...
The pool water temperature is maintained at 86-88 for the senior water aerobics classes that meet here 3 mornings/week. Most think that 86 is too cold. We also have 2 hour swim team practices every night, so I am sure that there is tons of sweating. Do you think that reducing the water temp to the low 80's would help improve the water quality much?
Thanks again for all of your advice! I will do what I can to implement the changes you recommend.
Uhhh ... no. That would be "Lisa." After a decade around here, you'ld think that you would have this all figured out by now -- who is who!! :rolleyes::p:):cool:Quote:
Originally Posted by PoolDoc
(JK!)
I just wanna say WOW to post #5. I got a lot of ideas from there regarding pool etiquette.
I think that I may be backwashing too often. My water is crystal clear, but I always backwash after vaccuming (about 1/week). I never see a pressure rise on my filters (other than maybe 1 psi). (I do not vaccum to waste. but rather, through the filters) They are Triton high-rate sand filters with no DE added (yet).
Thanks,
Mike
I got my Taylor 2006.
FC = 2.0
CC = 0.6
pH = 7.8
Regarding the CC-
It's indoors, so has little UV. Should I shock it with CL? Use MPS? Is Wipe-Out a good product? Would adding DE to my high-rate sand filters help?
Thanks,
Mike
I tested using MPS (potassium monopersulfate, Oxone) in various non-chlorine shocks, and got NO improvement. It screws up testing, because MPS tests as CC. And if you have an ORP/pH controller, you'll have to turn that off, and feed manually, because an ORP electrode sees monopersulfate as chlorine.
You can test DE; other than shortening filter runs, it shouldn't hurt anything. I haven't tried it myself, under those circumstances.
Don't know what "Wipe-Out" is -- do you have a brand and ingredient?
Here's what I've found helps:
#1 - Contamination control.
Doing something like having a 10 minute adult swim every hour so the "lifeguard can have a break" often works. You can tell, if you get the kids out, and they all start doing the pee-pee dance, before running for the bathroom. This can make a HUGE difference.
#2 - Keeping the pH at the high end of things (you're there now) seemed to me to reduce the noxiousness of the CC's, if not their levels.
#3 - Chlorinating with single doses of calcium hypochlorite, added at closing, in a very specific manner definitely helps.
I think I mentioned before that this approach took an overloaded and under-filtered Boys' Club pool with 300+ boys / day from hazy murky to crystal clear on Monday, and clear throughout the week. This is perfectly safe . . . IF you follow my instructions . . . but I don't usually explain this until somebody promises that they will dot their i's and cross their t's just like I say. And, of course you have to be able to purchase granular cal hypo, and have a location where you can add it AHEAD of the filter. (Skimmer, gutter, or surge pit)
#4 - I have speculated years ago that stabilizer, a low dose, might help. Chem_Geek has taken it further, and thinks that maintaining 10 ppm CYA will help. But, I'm not sure that anyone has really tested it. It won't hurt, unless you put too much in.
#5 - You can purchase a UV irradiation system, that adds outdoor-like UV + chlorine treatment of your pool. I believe these work - - like removing your cover would work - - but it's a major investment, and will significantly increase chlorine use.
[QUOTE=PoolDoc;75989]I tested using MPS (potassium monopersulfate, Oxone) in various non-chlorine shocks, and got NO improvement. #3 - Chlorinating with single doses of calcium hypochlorite, added at closing, in a very specific manner definitely helps.
I think I mentioned before that this approach took an overloaded and under-filtered Boys' Club pool with 300+ boys / day from hazy murky to crystal clear on Monday, and clear throughout the week. This is perfectly safe . . . IF you follow my instructions . . . but I don't usually explain this until somebody promises that they will dot their i's and cross their t's just like I say. And, of course you have to be able to purchase granular cal hypo, and have a location where you can add it AHEAD of the filter. (Skimmer, gutter, or surge pit)
Thanks!
I promise to dot my i's and cross my t's just like you say with calcium hypochlorite if you will instruct me....
I was about to buy a bunch of MPS (Wipe-Out is the brand at our supplier). Thanks- I won't.
To use cal hypo:
#1 - Find a location that allows you to add cal hypo directly to the return stream, going back to the pump.
#2 - Verify for an absolute certainty that, as you follow the flow stream from that point, there are no chemicals or chemical feed points between your location and the filter. No tabs. No injectors*, etc.
#3 - Verify for an absolute certainty that no one will dose other chemicals within 30 minutes of your dosing cal hypo.
#4 - Verify that you can turn off any ORP/pH controller* for at least 1 hour after dosing. Do NOT turn off the FLOW STREAM past the controller electrodes, but leave the controller on! Very, very dangerous, even apart from cal hypo dosing.
#5 - Make sure that the heaters are DOWNSTREAM of the filters (They should be, but check)
#6 - Make sure that if any stabilizer (cyanuric acid) is on the premises, that it MUST not be added to the pool without your prior knowledge and approval.
Get back to me on these.
Basically, though, you add cal hypo so that it and all the calcium debris are caught by the filter. This debris seems to enhance filtration. It also limits calcium and alkalinity build up . . . IF you let your pH 'float'. It may not work on all pools, but it has worked fine on every pool where I've tried it. Once you start this, cal hypo and stabilizer will be the ONLY chemicals you add to the pool.
BUT . . . cal hypo is incompatible with ALL other pool chemicals. It's fine, once fully dissolved but it must not come into direct contact with any other pool chemical. It detonates on direct contact with stabilizer, and if you add cal hypo while stabilizer is still dissolving on the filter, it will sound like you are cooking popcorn INSIDE the filter! (Don't ask how I know -- I was lucky!)
Also, when you dose it will totally whack out any ORP / pH controller you have -- so that MUST be turned off.
The best way to dose with with a full days (or close) chlorine dose added just after closing.
More details, after you confirm the items above.
#1 - I have a gravity flow collection tank that is fed by the gutters and is drawn from to the pump, then to the filters, through the heater, and back to floor inlets in the pool
#2 - I only have one chemical feeder, and I will unplug it.
#3 - I can lock the chemical storage room, and no one adds anything without my direction, and I can guard it for half an hour.
#4 - We don't use a controller
#5 - We just have one heater, and it is the last thing the water goes through before it returns to the pool.
#6 - We don't have any stabilizer (cyanuric acid)
#5 -Quote:
Originally Posted by PoolDoc
"Once you start this, cal hypo and stabilizer will be the ONLY chemicals you add to the pool." - Pool Doc
I don't understand....
Thanks,
Mike
This mornings test results:
FC = 0.8
CC = 0.4
pH = 8.0
CC decreased from 0.6 to 0.4 overnight with nothing added to the pool... maybe, as you supposed, the higher pH helped.Quote:
Originally Posted by PoolDoc
Not likely.
CC levels will drop, when your chlorine levels drop. Higher pH doesn't reduce CC levels; it just shifts CC production toward types that are less noxious -- I thing (it hasn't been proven).
But it looks like you are good to go on dosing with cal hypo. So, do this:
#1 - Get an old sock, and put enough stabilizer in it to raise it to 10 ppm in your pool; it won't show up on a test kit, but it WILL affect your pool.
#2 - Suspend the sock in the pit, where the CYA can dissolve (5 days?) but NOT be hit by cal hypo particles.
#3 - Wait 1 day after adding CYA
#4 - Clean your filter.
#5 - Get your cal hypo, and add a 3 ppm dose at closing, directly to the pit, preferably where all residue will be stirred up and end up on the filter.
By the way, since you have a pit, if there's any way you can
#1 - adjust things so that water SPLASHES into the pit, and
#2 - ventilate the room well
that may help a lot. Many of the worst CC's are somewhat volatile, and are at least partially removed by areation. But, the fumes are noxious and corrosive, so you've got to be able to ventilate.
Can you take pictures? I may be able to suggest things, once I've 'seen' your pool and equipment space and setup.
https://fbcdn-profile-a.akamaihd.net..._1432962_n.jpg
This is all that I have right now, but I will try put some more up later.
For coordination, note that there is a similar thread at TFP where I just posted here. As for the interference of MPS registering as CC, Taylor has a Taylor K-2042 reagent so you can distinguish between MPS vs. regular CC. I know that at the last NEHA conference that I went to there were a few people who were successfully using non-chlorine shock (MPS) to keep their CC's in check in high bather-load pools. The main downside is that it builds up sulfates over time and initially the MPS itself can be irritating (technically it's the potassium persulfate contaminant that is irritating) so it's probably best to add at the end of the day to give it overnight for the irritating contaminant to go away and for overall MPS levels to start out somewhat lower for the start of the day.
There are quite a few who use UV with success. That seems to be the most popular approach. Unfortunately, research is showing that it creates different disinfection by-products, but it does seem to get rid of the ones that are smelly/irritating and measure as CC. Ozone is another approach, but these things get expensive as you need a separate mixing tank with proper outgassing, especially for an indoor pool since you can't let the ozone level in the pool and therefore the air get too high (it's designed to be an off-line oxidizer and not a bulk-water disinfectant).
As for CYA, that will lower the active chlorine level which will lower the rate of creation of disinfection by-products such as nitrogen trichloride at first, BUT over time in indoor pools it will build up to a higher steady-state organics level since they will get more slowly oxidized so you have to remove those through other means. Even significant water dilution will help. Are you replacing 7 gallons of water for every person-hour of pool use? That's the APSP-11 standard and similar to the European standard of 30 liters (8 gallons). The main advantage of using the CYA is that it will buy you time for other supplemental oxidation to do the job of handling bather waste. It will also be slower to oxidize or irritate skin, hair and swimsuits. It is NOT a solution by itself and in the short-run may even show some CC increase if there is a lot of ammonia from sweat/urine, but it will be monochloramine and some dichloramine that are not nearly as bad (smelly/irritating) as nitrogen trichloride. Basically, the active chlorine level trades off between these three in the short-run as shown below:
Chemical ...... High Active Chlorine .... Low Active Chlorine .... Comments
Monochloramine ...... Lower ......................... Higher .................... Gets fully oxidized; note that tap water often has 1 ppm CC as monochloramine
Dichloramine ........... Lower ......................... Higher .................... Gets fully oxidized; is more smelly (odor threshold 0.1-0.5 ppm) but level will be about 1/6th that of monochloramine
Nitrogen trichloride .. Higher ........................ Lower ..................... Persists and outgasses and is smelly and irritating even at low levels (odor threshold is 20 ppb which is 0.02 ppm)
Your county/state regulations may prohibit you from having any CYA in a commercial/public indoor pool so be sure to check that first, though usually it's just a recommendation against using it because they think it's not needed since there is non sunlight. With a high active chlorine level, the monochloramine and dichloramine get oxidized on the order of 10 minutes or so while at a low active chlorine level it takes a few hours.
Chem Geek - I wrote a reply a couple of days ago, but it did not send properly or something. Thanks for your input here and at TFP. I am adding an average of about 700 gallons or so a day, which keeps up with evaporation, splashout, and backwash and rinse. I estimate that our swimmer hours/day varies between 50 and 100.
You meet or exceed the 7 gallons per bather-hour APSP-11 rule. So 700 gallons out of 100,000 gallons is 0.7% per day. You basically dilute your water by about 19% every month. While this certainly helps, it's not going to be enough to keep the chloramines in check by itself or with chlorine alone.
IF the eye irritation is from nitrogen trichloride that is higher due to your higher active chlorine level (2 ppm FC with no CYA earlier; now 0.8 ppm FC with no CYA), then using a small amount of CYA would lower the active chlorine even more where 2 ppm FC with 10 ppm CYA or 4 ppm FC with 20 ppm CYA would be roughly equivalent to 0.2 ppm FC with no CYA. Though this should lower the irritating nitrogen trichloride, it may increase over time the measured CC level though it will now mostly be chlorourea and monochloramine which are not as irritating. The problem is that your county/state pool codes may require you to have 0.2 ppm CC or less and don't care what the "type" of CC actually is. They may also forbid you from having any CYA at all. In that case, supplemental oxidation will be your only answer (unless you can get people to improve their habits to reduce organic load as Ben suggested) in the long run.