Pool Water Testing Blog

In an earlier post we discussed manual methods for testing copper levels in pool water: Traditional ‘Liquid’ Test Kits and Test Strips. While those methods work well most of the time, when the time comes to make a major decision regarding which way to direct a pool’s chemical balance, many people prefer to rely on the accuracy and impartiality of digital testing meters.

In this installment of the Pool Testing Blog we will discuss two electronic water testing meters designed to accurately test dissolved copper levels in pool water.

• Color Q Copper 5 — Manufactured by Lamotte, uses liquid and tablet reagents, and provides direct read measurements for the following: pH, alkalinity, calcium hardness, iron, and copper.

  • pH Range: 6.5-8.5

  • Alkalinity Range: 0-250 ppm
  • Calcium Hardness Range: 0-700 ppm
  • Iron Range: 0-3.0 ppm
  • Copper Range: 0-4.0 ppm

• eXact Micro 7+ Pool/Spa Meter — Manufactured by Industrial Test Systems, uses reagentstrip delivery system and liquid reagents, and provides direct read measurements for the following: pH, alkalinity, calcium hardness, copper, cyanuric acid, free chlorine, and total chlorine.

  • pH Range: 6.2-8.4

  • Alkalinity Range: 20-180 ppm
  • Calcium Hardness Range: 20-990 ppm
  • Cyanuric Acid Range: 5-62 ppm
  • Free Chlorine Range: 0-6.0 ppm
  • Total Chlorine Range: 0-6.0 ppm
  • Copper Range: 0.04-8.0 ppm

The presence of dissolved copper in tap, well and drinking water can cause problems, including health problems, and it can also cause problems in pool water. Most pools use some form of strong oxidizer (i.e. chlorine, bromine, etc.) and with the right pH those oxidizers can cause the dissolved copper to drop out of solution and stain pool surfaces.

In the event of copper staining, pool owners must usually resort to spending money on stain removal chemicals from companies such as Jack’s Magic. While these chemicals work very well, most people would prefer not to have needed them in the first place.

When it comes to metals like copper in pool water, an ounce of prevention in the form of testing can prevent (literally) quarts and gallons of aggravation in the form of stain removal chemicals… which typically cost more than $20 per quart!

Methods of Testing Copper in Pool Water

Traditional methods for testing copper in pool water required the use of liquid, tablet and/or powdered reagents (see Taylor Copper Test Kit) while newer methods include the use of ion-specific tests strips (see AquaChek Copper and Pool Check Copper).

Electronic meters exist for testing copper in pool water as well, but we will go into detail about those in an upcoming post. For now we will concentrate just on popular visual testing methods for copper in pool water.

• First, you have the AquaChek Copper Test Strips which come packages in bottles of 25 and have detection levels of 0, 0.2, 0.5, 1, and 3 ppm. Approximate cost: $12.

• Next you have the Pool Check Copper 3 in 1 Test Strips which come packaged in bottles of 50 and test for copper, pH and alkalinity all at the same time. This product has copper detection levels of 0, 0.2, 0.4, 0.7, 1, 2 ppm. Approximate cost: $15.

• And last but not necessarily least, you have the Taylor Copper Test Kit which uses a pair of liquid reagents and detects between 0 and 3 ppm copper. Approximate cost: $44.

With regard to which of the three aforementioned methods works best, well, each has its place at the copper testing table… though we do favor the Pool Check Copper 3 in 1 Test Strips because of their color chart has the most useful level designations for copper testing while also testing for pH and alkalinity at the same time.

For the longest time pool and spa owners had to rely on the chemical testing skills and expertise of their local pool and spa professionals but those days have passed. Now homeowners can test their own pool and spa water for metals — without having to take a year’s worth of chemistry courses!

* The Pool Check^TM Copper test strips offer fast, accurate test results for copper, pH and alkalinity at a reasonable cost.

* The Pool Check^TM Pro Metals test strips offer fast, accurate semiquantitative test results for ‘all’ metals at once. It does not specify which metal(s) it detects, but it does give pool owners a better idea of how much staining potential their pool water has.

* The eXact^R Micro 7 pool and spa testing meter tests for many parameters including iron and copper.

* Other testing methods include using ‘wet’ chemistry kits from companies like Lamotte and Taylor, but they typically involve slightly more advanced testing techniques such as titrations. Wet kits also make use of messy dpd liquids, difficult to dissolve dpd tablets, and awkward dpd powder pillows.

For those who suspect that their source water contains metals, the SenSafe^TM Metals Check test strip will work quite well. It detects the metals commonly found in tap water and well water and provides accurate metals testing results in under 3 minutes.

Can Metals Stains in Pools be Removed?

For the most part, yes. The task will take effort, though, in some cases.

Vinyl liners typically resist staining quite well but the stains that do set in will not come off without a fight. Pool owners must use sequestering compounds and/or chelating compounds which attach themselves to the metal stains/deposits and more or less pull them back into solution. (See Jack’s Magic)

Owners of concrete and gunite pools suffer even worse fates when it comes to metals staining. Typically they must wash the stains away using diluted muriatic acid — and in some cases that means draining the pool completely before they can begin.

Due to the annoyance, expense and inconvenience associated with the removal of metals stains from pool liners and plastic fixtures, swimming pool professionals recommend testing for metals on a regular basis if the pool has a heater, uses a copper or silver ionizer, or has recently had water added to it that may have contained dissolved metals.

In unbalanced water, copper may ‘drop out of solution’ and cause staining of a pool’s submerged fixtures and pretty much all of its non-metal surfaces (i.e. vinyl liner, fiberglass bottom, concrete/gunite bottom, etc.). Typically a severe drop in alkalinity and/or pH can result in copper staining with the right amount of free dissolved copper present.

In the case where the pool in question has a heater tests for copper in pool water yielding positive results may mean the pool water has become corrosive and has started to eat away at the copper in the heating element(s) in their heater.

A second source of copper, and also a good reason to test for copper in pool water every once in a while, has to do with the pool owner’s choice of algaecides. Some of the algaecides on the market contain trace amounts of copper due to copper’s ability to effectively fend off an outbreak of algae in water whose chlorine or other oxidizer level has dropped. Long-term use, or most often improper overuse, of copper-based algaecides can lead to an excessive buildup of copper in the water. A severe change in alkalinity and pH, possibly as a result of a rainstorm or the addition of ‘new’ water to the pool, may cause that copper to ‘come out of solution’ and cause staining on the surfaces mentioned earlier.

Does Copper in Pool Water Always Mean Trouble?

Absolutely not! In fact, some pools rely on copper as their primary algistat and use very low levels of oxidizers such as chlorine to destroy any organics that do attempt to make the water their new home.

How Can Pool Owners Test for Copper in Pool Water?

Pool owners can test for the presence of free dissolved copper in their pool water using traditional wet kits, by taking a sample of their pool water into their local pool store for analysis, or by using a test strip such as the Pool Check^TM Copper test strip which detects free dissolved copper levels as low as 0.2ppm and as high as 2.0ppm in under a minute.

The Pool Check^TM Copper test strip also tests for pH and Alkalinity at the same time it tests for free dissolved copper residual. This product tests for pH and Alkalinity because they changes in those two pool water parameters can cause free dissolved copper to come out of solution, settle on surfaces, and stain whatever it lands on — sometimes permanently!