Years after the start-up is finished, changing water conditions can still damage and stain plaster in some surprising ways.<\/p>\n
Gary Gripp\u2019s story begins like so many others.<\/p>\n
\u201cI\u2019d been servicing pools in this area for over 15 years when it happened,\u201d says the service manager at Anderson Poolworks in Portland, Ore. Gripp and his team had been hired to drain, clean and refill a gunite pool, and everything seemed to have gone right. \u201cWhen we left the job site, that plaster was clean as new, and the water was sparkling clear,\u201d he says.<\/p>\n
But the next afternoon, the customer called again, complaining that the pool\u2019s water was grayish.<\/p>\n
Gripp was hurrying back to the job site when he answered another call from the same customer, the water had now turned a pale shade of lavender.<\/p>\n
\u201cAnd by the next day,\u201d he says, \u201cthe water was this beautiful deep purple \u2014 like a jewel. I wouldn\u2019t have even guessed water could turn that color.\u201d<\/p>\n
The culprit, Gripp discovered, was manganese, a metal known to lend a distinctive range of tints to water: Grayish at lower concentrations, up through brighter shades of purple at higher ones. The real question was, why had manganese suddenly become such a problem for this pool?<\/p>\n
\u201cWhen we tested the fill water, we found that the manganese levels coming out of the tap were just about off the scale,\u201d Gripp says. Luckily, he\u2019d managed to pinpoint the problem before the manganese stained the plaster, and was able to bring the water back into balance with a sequestering agent.<\/p>\n
Still, Gripp says he learned something crucial from the experience. \u201cNo matter how long I\u2019ve been working on a pool,\u201d he says, \u201cI don\u2019t assume anything anymore. I test the fill water on every visit, sometimes even multiple times. Your chemistry could be perfect, but until you test your makeup water you never know what it could be depositing into the system.\u201d<\/p>\n
As builders and service technicians around the country have confirmed, balanced water chemistry is a science \u2014 and, in its own way, an art \u2014 that reaches well beyond the start-up. Even years down the road, calcium hardness, total alkalinity, pH and other factors can shift dramatically, sometimes in a single day.<\/p>\n
Even so, a little preparation and a lot of thoroughness can help stop these problems before they damage the plaster.<\/p>\n
Chemical crawl<\/strong><\/p>\n Changing water chemistry can seem to sneak up on you. Its effects, however, are often \u2014 though not always \u2014 the results of conditions that have been building up for some time.<\/p>\n Take metals, for example: Their level in the water can gradually rise due to a variety of factors. In dry or windy areas, evaporation removes water but leaves dissolved solids (including metals) behind, significantly raising the water\u2019s total dissolved solids over time. If someone\u2019s been adding a copper algaecide without testing the level regularly, the water\u2019s copper level can rise even more quickly.<\/p>\n Metal deposits inside pipes can be harder to detect, and they often accumulate for years before leading to a problem. \u201cAt every pool I\u2019ve seen that\u2019s been around for a few years,\u201d Gripp says, \u201cyou can cut a pipe open \u2014 even a PVC pipe \u2014 and see a deposit of some kind in there. It may be clear and slick, but something always accumulates.\u201d<\/p>\n Most pool water contains some amount of dissolved metals, but these are typically harmless, and invisible to the naked eye. Nevertheless, a variety of common chemical reactions \u2014 such as the breakdown of hypochlorous acid under UV radiation and the electrolysis of saltwater in a chlorine generator \u2014 increase the water\u2019s concentration of \u201cfree\u201d oxygen, the form necessary for oxidation to occur.<\/p>\n The more free oxygen that becomes available, the more metals in the water begin to oxidize \u2014 that is, they bond with the free oxygen, which converts them into oxides. Oxidization causes the metals to precipitate out (or fall out) of solution and become visible as a tint in the water. The longer this oxidation reaction is allowed to continue, the greater the risk that the metal oxide will stain the plaster \u2014 and eventually be absorbed by its surface.<\/p>\n This is most common with copper, particularly in areas that experience severe storms or droughts, like the Gulf states, says Jana Auringer, owner of The Pool Lady in Coppell, Texas. Auringer travels the Southwest as a consultant, tracking down the sources of plaster stains. She says copper\u2019s telltale pale green tint often appears in pools that experienced no staining issues prior to a bout of harsh weather, and it\u2019s usually traceable to a chemical change in the pool\u2019s fill water.<\/p>\n \u201c[After a storm or drought], we\u2019re finding higher levels of copper in the source water when we test it,\u201d she says. \u201cA lot of times, though, the metal won\u2019t show up on water tests, because it\u2019s already precipitated out and stained the plaster.\u201d<\/p>\n Sudden shifts<\/strong><\/p>\n Stains and other plaster issues don\u2019t always sneak up so gradually, though. As Gripp discovered with his purple pool, water\u2019s composition can seem to change dramatically in just a few days. Sometimes, water whose chemistry has remained stable for years will suddenly display a sharp drop in calcium hardness or total alkalinity. In those cases, servicepeople say, it\u2019s probably not the same water at all.<\/p>\n Across the country, builders and service pros confirm that municipal water circulation has become more complex over the past few years. These days, the water that flows from a tap is a mixture of water from wells, rivers, reservoirs and storage tanks, and the proportion of water drawn from each source may vary from day to day.<\/p>\n Lance Sada became so frustrated by the seemingly random water chemistry he encountered on his route that he performed his own chemical survey. Using a series of brand-new test kits, the owner of A Clear Choice Pool and Spa Service in Sun City, Calif., tested the water up and down residential blocks in his area. \u201cI found that from one street to another, the water\u2019s calcium hardness might be as low as 20 ppm, or as high as 200,\u201d he says. \u201cSometimes, the hardness from a single tap varied by 100 ppm from one day to the next.\u201d<\/p>\n In cases like these, the most effective way to prevent problems is to test the pool\u2019s fill water on every visit, before adding any chemicals. But in other situations, the source water itself is less of a problem than what it dredges up.<\/p>\n \u201cSome customers get an accumulation of metal deposits in the bottom of their well,\u201d Gripp says. \u201cWhen you kick that well on, an abundance of iron, copper, manganese \u2014 whatever accumulated in that well source \u2014 will come flying into the pool during the initial burst of water.\u201d<\/p>\n Pools that sit idle for the winter tend to display similar symptoms when the weather heats up. \u201cIf you shut a pool down for a period of time and you don\u2019t empty the chlorinator, or run the chlorine off beforehand,\u201d Gripp says, \u201cthat chlorine\u2019s chewing away at the copper or iron inside the pipes.\u201d When you turn such a system on, it may kick a cloud of metal oxides into the water, and create stains on the plaster.<\/p>\n Perhaps strangest of all, some stains only appear after a plaster surface has been freshly cleaned. \u201cA degraded surface sometimes doesn\u2019t attract stains because it\u2019s so heavily scaled, or has some type of mineral coating on it,\u201d Gripp explains. \u201cAnd when you resurface it, you might find that your water chemistry looks fine, but all of a sudden you get a stain around the return.\u201d Those stains are most likely metal oxides, to which the plaster\u2019s exposed surface is suddenly vulnerable.<\/p>\n Even if you\u2019re anticipating unpleasant surprises like these, they can\u2019t always be avoided. If you start investigating as soon as you notice discoloration, though, it\u2019s often possible to prevent a metal oxide from becoming a permanent plaster stain.<\/p>\n Getting proactive<\/strong><\/p>\n Diagnosing the source of a discoloration takes a lot more than educated guesswork. Each pool\u2019s chemical conditions are unique. Manganese, for instance, can appear as a gray, black, lavender or purple stain, depending on the chemistry of the surrounding water. A high TDS reading may point to an excessive level of contaminants, or it might mean you\u2019re adding too much of a particular chemical \u2014 or any number of other issues. That\u2019s why it\u2019s crucial to pinpoint the problem\u2019s origin, then confirm it with multiple tests, before you start any treatment.<\/p>\n To become a master of plaster problem-solving, you\u2019ll need to focus on two related skills: Investigating all factors that affect the system, and confirming test results before starting to treat the issue.<\/p>\n The first skill, though it might seem overwhelming at first, is mostly a matter of knowing what questions to ask the customer, and listening carefully to the answers.<\/p>\n \u201cYou\u2019ll need to get some background on when the owner first started seeing the discoloration,\u201d Auringer says. \u201cWas it after a heavy rain? After shocking the pool? After a new type of algae treatment? Try to find some change in circumstances to tie the problem to.\u201d<\/p>\n It may also be helpful to find out if any equipment has been replaced, and ask to see the house\u2019s plumbing to check if water has been running through old copper or iron piping. It\u2019s also important to understand the history of the pool\u2019s maintenance regimen, who\u2019s been working on the pool, and what\u2019s been added to the water over time. This can often lead to surprising (and useful) answers.<\/p>\n \u201cIt might sound like a lot,\u201d Gripp says, \u201cbut if you take every pool on a case-by-case basis, you can find out everything you need to know in a 10-minute conversation.\u201d<\/p>\n The second skill is also somewhat of a matter of instinct, but it too can be boiled down to some basic principles. Techs agree that you\u2019re doing yourself a favor by testing on every visit, in more than one spot in the pool, and by testing source water regularly.<\/p>\n \u201cAlways start with a clean slate, and test the tap water first,\u201d Gripp says. In fact, the first time he visits a site, he runs through every single test in his kit. \u201cWe also use the separate tests for manganese, iron, copper, phosphates and \u2014 if it\u2019s applicable \u2014 salinity,\u201d he adds.<\/p>\n Testing the water at several spots around the pool, then averaging the results, can help prevent inaccurate readings due to dead spots or other circulation problems. \u201cEvery time I\u2019ve tested multiple spots in a pool,\u201d Gripp explains, \u201cthere are significant pH, alkalinity and chlorine differences between them.\u201d<\/p>\n Garrett and Gripp both recommend holding onto your results from the source water, and comparing them against your test results from around the pool for confirmation. \u201cWhen you go to the doctor,\u201d Garrett says, \u201che\u2019s always going to check your blood pressure, pulse, temperature and so on, because that gives him a baseline reading to know if there\u2019s anything else wrong with you. It\u2019s no different for pool chemistry: You need to establish a baseline before you know what you need to adjust.\u201d<\/p>\n Finally, before acting on your test results, it\u2019s important to confirm them with other testing methods. At the very least, your test kit should be calibrated against a set of chemical standards, which are usually sold by the kit\u2019s manufacturer. You can also ensure the accuracy of your results by confirming them against another type of test, such as an electronic meter or test strip.<\/p>\n \u201cAnd that makes you so much more confident when you speak to the homeowner,\u201d Gripp says, \u201cbecause you can show them the results of multiple tests that all confirm each other.\u201d<\/p>\n Source: Ben Thomas- Pool and Spa News | 2.11.2011<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" Years after the start-up is finished, changing water conditions can still damage and stain plaster in some surprising ways. Gary Gripp\u2019s story begins like so many others. \u201cI\u2019d been servicing pools in this area for over 15 years when it … Continue reading \n\n
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