Most people that watched the Rio Olympic diving events couldn’t believe how the dive pool turned green and murky. They also marveled at how the water quality failed to recover for days. What could have happened? and how can we avoid this kind of catastrophe in our facility pools?
It was an embarrassing mess, wasn't it.… especially with the whole world watching, and with 4 years to prepare for the event.
Most alarming were the series of lame excuses that were provided while little progress was made. Some of the internet favorites were:
- Pool was green due to heat and “lack of wind”. Honestly?
- "Chemistry is not an Exact Science"
- Pool was green due to the "Proliferation of algae"
- "pH was thrown off by the large number of people using the pool"
- Events were cancelled because: Water must be "still so it can return to its blue color".
While Karma dictates that you don’t ever want to make light of other people’s bad fortune, we need to understand and learn from this type of mess-up.
There are three major causes of murky or green water, namely metals, poor filtration, and poor oxidation. Here’s a quick look of the typical cause and solution for each of these.
Sister Pool started turning color as well.
Swimming pools are very susceptible to metals build up. Why? While all pools continually receive metals from the city water supply, they accumulate faster in pools due to higher evaporation. When water evaporates, pure (or distilled) water escapes, leaving behind all the minerals, metals, salt, etc… and when new water is introduced, the new metals ADD to the total metal count. BUT, metals will tend to stay invisible (or "in solution"), even at fairly high levels, and you need an “triggering event”, normally high pH, to drop them out in the water – turning the pool green (either clear or murky). Restoring the correct pH will prevent additional metals from dropping out, but will not put the copper "in solution" (invisible) again, and you will need a way to remove the “dropped out” metals from the water – and some filters just can’t do the job.
Test your metals monthly using a Palintest9 test kit or equivalent, and dump water (different than evaporation) to keep the water from getting too overstuffed with minerals and metals. You should also use a sequestering agent such us Jack’s Magic or Metal & Stain Inhibitor (MSI) to keep metals in solution and to drop them out gradually through the filter. If you have a “Rio” event, you can first drop the pH and then use a filter aid or special copper-removal chemical to drop copper through the filter fast.
Poor Filtration continually puts you at the edge of disaster, and once you have an event, it becomes very difficult to recover. With poor filtration the filter might seem "lethargic" in being able to maintain or restore clarity. In fact, one of the differences between poor oxidation and poor filtration in cloudy water, is that poor filtration can help the condition linger for many days or even weeks, where cloudiness from poor oxidation can be cured by a simple overnight shock. Also, even the best filter can fall into disrepair over time if proper preventive maintenance is not provided periodically.
Install a filter that is capable of providing the desired water quality initially, and keep pace with required maintenance on an annual basis. In case of a filtration event, you can use a “blue-type” clarifier, or you can pre-coat the existing filter (regardless of type) with a small amount of cellulose wood fiber such as Jack’s Magic Fiber Stuff™ or similar. The clarifier or wood fiber will enhance the filtration temporarily, but you need to resolve the underlying issue before it becomes as bigger problem. Also CES stocks special chemicals designed to remove copper from pool water through the filter media, so we can assist if you ever are confronted with this type of issue.
Poor Oxidation, as evidence by low ORP, and displayed in cloudy or lifeless water can happen quickly during a lapse, or can happen as a small deficiency over a long period of time. If your oxidation rate (ORP) is low, organics and other stuff will accumulate in the pool water. The residual of bad stuff (AKA Chlorine Demand) could reach 50-100 PPM, so it is immune to most treatments or shocks. You can’t really see this stuff, nor can’t easily test for or anticipate it, but eventually you will have a very “sick” pool that can turn on you very quickly, and can be very difficult to correct. Also a sick pool can gobble up exponential amounts of chlorine to generate the same ORP or Chlorine residual.
High pH will also cause the ORP to drop, potentially causing the reported "algae" bloom, but algae blooms seldom produce that clear of a green-colored water. High pH, as Rio reportedly ran out of pH chemical, would also have caused the green metal to drop out (see above).
Also it was reported that someone introduced a large amount of hydrogen peroxide into the pool water as a treatment. Big Mistake. The "adverse reaction" reported by NBC and others is that it will effectively not only dechlorinate the pool, but will form a chlorine deficit that will chew up most of the chlorine you add to the pool for hours or days. Yikes.
Since a shock that doesn’t reach the Chlorine Demand threshold is worthless, traditional treatments have limited benefits. A CES Peroxolyte shock will bring the pool to a high ORP, burn up the bad stuff, and return to normal within a few hours, making it a magic “drug” for most types of cloudy water ailments. However, the strategy is to prevent this from occurring in the first place by monitoring your Chlorine and ORP levels daily, and paying careful attention to the relationship between the two. The higher the ORP the better (750mV and up is good and 800mV & up is much better), but anything less than 700 mV is considered sick, especially if it takes more than 2.0 PPM to get there.
Another solution is to always have an acceptable amount of chemicals on hand -- especially if you are hosting the Olympics. This would like you running out of ice at your home reception party when your child get married.
A 3rd solution is to prevent poor oxidation is to prevent rookies from throwing anything in your pool water without checking with you first. This happens all the time, and could happen just as easily in your home pool, municipal pool or condo.
The three categories above have traditionally accounted for most of the “losing your pool” events, although many times the issues are layered. So in the Rio example, they might have had a high metal count (no pun intended) going into the games, then let the pH go high, thus triggering a dropping out of copper and the clear green look. Once they de-chlorinated as a byproduct of their Hydrogen Peroxide treatment, the ORP could have plummeted and offered little chance of oxidizing the pool back to the normal color. The water could then have continued to deteriorate turning into the murky green. They also didn't implement any action to remove the green color through filtration, and they reportedly were changing out the media in the filters. Finally, they ended up (reportedly) dumping 1 million gallons and exchanging it with the outdoor water polo pool. Too little too late.
In any event, a more conscientious or a better-prepared operator could have seen the warning signs and could have avoided this entire mess. They would have had adequate chemical on hand for the event, and could have had both the treatment and filtration systems from these 2007 pools in better condition with preventive maintenance. They also could have responded with a more suitable "action" once the issue took place.
By comparison, the (13) Myrtha Pools installed specifically for the Olympics we clear and blue. They had good filtration systems, and were professionally operated during the entire swimming competition.
We're NOT trying to be critical of the operators, but the operations were apparently flawed. Then again, this type of public foopah validates why so many CES customers invest heavily in education for their staff, and establish vital checks and balances in their daily action plans. On a final note, in the case of an event many customers have learned to be very careful with what they say, as lame excuses may end up as a lightning rod for criticism, from a condo board... or in this case from the internet.
Hope this helped, and please let us know if we can ever be of assistance.