Need help with algue in a oxygen pool

[PMS SAyMI]

Hi,

First let me Introduce myself My name is Amanda and I have a Pool construction, repairs and maintenance company here is southern spain.

My problem is I seem to have a ongoing problem with algue in a indoor pool, the pool was orginally chlorine then the client requested we change it to oxygen as she found the chlorine was irratiting her skin. As the pool had a problem with green algue (slimy but only in the grout) and the fact it never gets fresh water as is topped up from a built in water hold we decided it would be best to empty, clean and refill then add the oxygen.

However now 2 months on although not bad at the min, the grout problem seems to be returning all Chemical levels are within good paramiters apart from Alkalinity and I use the Palintest photometer so feel sure my levels are right.

Any help would be great.
Amanda

[PoolDoc]

Hi Amanda;

It may be an vocabulary problem . . . but I don't know what you mean by "oxygen". If you mean, simply O2 -- diatomic oxygen -- it's not a sanitizer or an algaecide. If you mean ozone -- O3 -- it is an effective oxidizer and sanitizer, but an ineffective algaecide.

I'm familiar with the Palintest products from 15 years ago, but not their current product line. Are you testing with tablets added to pool water samples? If so, those results are meaningful. But, if they've come out with test strips, then you'll need another testing method before we can make any judgements.

Also, I don't know what products you have available in Spain. The Buckman polyquat product line would probably be effective, and functional in an ozonated pool, but I don't know if that's available there, since Buckman is a fairly small US company, and they still have a patent. (The patent on the product expired, but they have had an unexpired patent on a feed stock component.) You could use what are called linear quaternary ammonia compounds, but they tend to make the water foamy, and can be quite irritating.

If you can tell us what you are currently using in the pool (besides "oxygen") and what you have available, we might be able to offer some advice. But you'll need to use chemical names, rather than brand or product names. Even US based companies tend to change product names on a country by country basis.

[chem geek]

The chlorine may have been irritating her skin because you may have been using unstabilized chlorine (sodium hypochlorite or Cal-Hypo) without any Cyanuric Acid (CYA) in the water, possibly because you thought that as an indoor pool it didn't need any CYA. However, without CYA in the water, the active chlorine level will be much higher. Even 1-2 ppm Free Chlorine (FC) with no CYA is 10-20 times more powerful and potentially irritating than 3 ppm FC with 30 ppm CYA where this latter amount is more than sufficient to prevent algae growth.

The Palintest SP 315C has the same tests as the Taylor K-2005 except possibly no acid/base demand test and is a decent alternative for those who can't get Taylor kits overseas. It uses tablets for most tests, but uses DPD for FC and CC and tests for TA and CH via count the drop tests (I think) and tests for CYA with a turbidimetric test. However, Amanda mentioned a "photometer" so this sounds completely colorimetric for all tests (well, still turbidimetric for CYA). I'm sure waterbear is familiar with these.

[PoolDoc]

Richard,

I think I understand your reasoning on this . . . and it's reasonable. But I'm just not sure it's completely correct, for the simple reason that my experience, and that of my sons and my wife, in indoor pools with varying levels of chlorine (0.5 - 30 ppm) with ZERO stabilizer, is not completely consistent with your theory.

Put simply, our experience is that chlorine with minimal organics (fewer swimmers per gallon, no lotion, + 80 F.) is not very irritating, even at levels high enough to turn hair from brown to ash colored. It DOES dry the skin. But with high organic &/or nitrogen loads (lots of swimmers, pee, sweat, & lotion + 87 F.), even low levels are irritating (dry skin + itch + red rash). And the particular pool my wife worked in for 10 years remained irritating. I even tried using 10 ppm of CYA once -- probably 15 years ago, now. My sons were mostly in large pools with few swimmers. My wife was in a small pool with many swimmers, and had to coat her skin with lotion before entering to keep the problems manageable.

So, while your explanation is both plausible and reasonable, it's not completely consistent with our experience. Unfortunately, careful confirmatory research on this topic would be really, really hard.

[chem geek]

Higher bather load pools, such as commercial/public pools, are a different animal. In those, one can have many more intermediate chlorinated by-products and some of these may be irritating. For Amanda's customer, it sounds more like a residential pool and at typical low bather load the chlorine itself *might* be irritating, depending on its level, but for most people it is not. Most tap water is chlorinated, so if this customer showers or takes baths and doesn't get irritation then they might not actually have a problem with chlorine (unless the tap water is chloraminated, which is monochloramine).

I just know that my wife hates swimming in our community center indoor pool over the winter because her swimsuits only last one season (elasticity gets shot) and her skin gets flakier and hair frizzier (though she never complained of irritation). In our own pool during the summer, none of these problems occur and her swim suits last for many years. The main difference is that the indoor pool has 1-2 ppm FC (sometimes more) with no CYA while our outdoor pool has 3-6 ppm FC with 40 ppm CYA which has the same active chlorine level as roughly 0.1 ppm FC with no CYA so a 10-20x difference. More than enough to account for at least the swimsuit degradation difference.

Anyway, if the customer truly does not want to use a halogen-based system (i.e. chlorine or bromine), then for pools the only other EPA-approved option is Baquacil/biguanide/PHMB with its own issues (and Amanda is in Spain where the regs are different anyway). For algae control, Polyquat 60 algicide used weekly should help.

[PoolDoc]

For Amanda's customer, it sounds more like a residential pool and at typical low bather load the chlorine itself *might* be irritating, depending on its level, but for most people it is not. Most tap water is chlorinated, so if this customer showers or takes baths and doesn't get irritation then they might not actually have a problem with chlorine (unless the tap water is chloraminated, which is monochloramine).

It's my suspicion that most of the "I'm allergic to chlorine" complaints -- except that it's usually a 3rd party who's allergic, like "my wife" or "my son" or "my customer" -- we get here are either psychosomatic in origin, or else misdirected blame. Otherwise as you note, you'd have a bazillion people who were complaining, "I'm allergic to my tap water". Unfortunately, I can't push hard to figure out what's going on, because the poster will either bail, or else be deeply offended, ie "How can you say that my darling wife is imagining it".

So, my suspicion will have to remain suspicion, and not conclusion. However, I still have seen ZERO evidence that chlorine ALLERGIES exist, and only suspect evidence that chlorine SENSITIVITY exists. (I have seen clear evidence that some people have more sensitive skin, than others do, to any sort of irritant.)

I just know that my wife hates swimming in our community center indoor pool over the winter because her swimsuits only last one season (elasticity gets shot) and her skin gets flakier and hair frizzier (though she never complained of irritation). In our own pool during the summer, none of these problems occur and her swim suits last for many years. The main difference is that the indoor pool has 1-2 ppm FC (sometimes more) with no CYA while our outdoor pool has 3-6 ppm FC with 40 ppm CYA which has the same active chlorine level as roughly 0.1 ppm FC with no CYA so a 10-20x difference. More than enough to account for at least the swimsuit degradation difference.

I agree that there's strong evidence that CYA ameliorates chlorine's effects on suits.

By the way, I'm beginning to wonder if some of the US pool fraudsters have migrated to Europe and started hawking "oxigen" or "oxygen" as a sanitizer or what not. If so, I'd say, good riddance to bad rubbish, but I'm sorry for the Euro pool owners getting defrauded.