Salvation Army Pool eye irritation

[PoolDoc]

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.

[SalvationArmy]

[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.

[PoolDoc]

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.

[SalvationArmy]

#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 -

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.


How do you "let pH float" - just let it go where it will for a while?
I do not understand "
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.

[SalvationArmy]

"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

[SalvationArmy]

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.

#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.

[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.

[SalvationArmy]

This is all that I have right now, but I will try put some more up later.

[chem geek]

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.

[SalvationArmy]

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.