Troubleshooting pool water problems

Oddball pool water problems

There's a song about TROUBLE. Troubleshooting is my favorite thing to do because most pool dealers or "experts" look at treating symptoms; getting to the root cause & solving the actual problem is what's called for!

Let's briefly look at:

  • Copper or Purple cyanurate staining
  • Truth about phosphates
  • The beauty of Enzymes & preventing icky scum lines
  • Preventing scale & scum on water features


Copper or Purple Cyanurate Staining

Beautiful but not pretty

Purple  or Copper Cyanurate is caused when the Cyanuric Acid (chlorine stabilizer or conditioner) is allowed to become "high" or over  100 ppm and it then reacts with any copper that may present in the water.  (Why I am so adamant about proper water testing & analysis.)

Purple Cyanurate is a chemical/mineral  imbalance problem. It is NOT an "organism" or algae problem.

Furthermore, it can appear that the staining is similar to  "crystals". Purple Cyanurate can not be easily scrubbed, scraped or  removed. It must be  treated chemically.

Purple Cyanurate is most often seen in the  spring at pool opening. Although it has been "noticed", cooler water (under 68  degrees Fahrenheit) helps this reaction more readily occur.

Purple or Copper Cyanurate is further made worse by the following water  balance issues:

  1. High pH - over 7.8
  2. High Total Alkalinity (TA) - over 150 ppm
  3. High Cyanuric Acid (stabilizer, conditioner) level over  100 ppm. For this reason alone it is NEVER a good idea to add CYA or stabilizer  unless the water has been properly tested & analyzed. CYA should NEVER be added unless the level is BELOW 30 ppm. At spring opening it is always a good idea to allow the water to circulate for at least 48 hours continuously with the return jets or fittings pointing to the bottom of the pool to create better overall  circulation. Also keep in mind that when testing pool water, high CYA levels can  & will produce an INACCURATE Total Alkalinity level. Proper testing, analysis &  balancing is required to correctly adjust the TA and pH.
  4. Copper present in the water - especially if over 0.5 ppm.  Copper can come from a variety of sources: home piping, pool heater, certain  algaecides & ionizing systems, etc.

When  all of these factors come together, you will experience the staining that you  see in the picture. THIS IS NOT PINK SLIME!

Prevention of "Purple or Copper Cyanurate" is preferred over treatment. Follow these steps to prevent Copper Cyanurate: 

  1. Maintain proper water balance: pH 7.4 - 7.6, TA 80 -  140 ppm, Calcium hardness 175 - 250 ppm. 
  2. Only add stabilizer in Chlorine  treated pools AND only when the CYA level drops below 20 - 30 ppm. If you are  using a slow-dissolving type of chlorine tab or stick, those products will  naturally release CYA into the pool over the course of the summer.

Only  use copper based algaecides when treating severe algae problems.


  1. Reduce the CYA level to under 30 ppm by partially draining & refilling the  pool with fresh water. After a partial drain & refill, allow the water to filter  & circulate for 48 hours before testing.
  2. Reduce the amount of copper  present in the water. 
  3. Properly adjust the pH & TA
  4. Add an initial dose of Jack's  Magic Blue or Pink Stuff has provided excellent & quicker treatment of the purple staining  (we prefer Jack's Magic products because they do & will work in pools when the  chlorine level is HIGH (between 3 ppm & 10 ppm).
  5. Be patient! The  Purple will eventually (sometimes as long as 4 to 6 weeks) to be re-absorbed  into the water. There is NO quick fix. 

An actual example of Copper Cyanurate staining from one of our customers. It is treatable!
An actual example of Copper Cyanurate staining from one of our customers. It is treatable!

The truth about Phosphates & Nitrates

Almost a nothingburger... almost

Phosphates & Nitrogen are 2 naturally occurring elements in nature.  Phosphorous is a mineral & nitrogen is a gas. In  nature, they don't cause or contribute to pool problems. However when they  are "added" to the pool water, problems can arise -- especially in a  poorly maintained situation. 


The two most  significant problems are moderate to severe algae blooms and chlorine demand. Both elements are essentially set up as a buffet table for any algae to just  come, eat & thrive.

Phosphates typically come into the pool from "un-natural" sources such as lawn care products; fertilizers, sprays, etc. These  lawn care products can be brought in from people walking on freshly treated areas where they are literally walked into the pool.  They can also "drift"  in when sprayed or just due to a windy day.  Remember, phosphates can come  from your yard, your neighbor's yard or even from someone you don't even know  who lives 3 blocks away.

More significantly, are the "natural" sources of Phosphates: basically, anything dead. Shower before entering the pool to minimize dead skin cells on your body. Plus, add in dead hair, dead leaves or grass, urine (everyone leaks a little bit), pets that may use the pool (read more here). And then there are the bird fly-overs.  Sorry to be indelicate, but bird poop will be a serious trial for any pool  owner!

1 Kilogram of phosphates can aid in producing up to 500  kilograms of algae (Panda.org).

Although difficult to completely eradicate, phosphates can be controlled by using phosphate removers such as ActivNzyme, an enzyme cleaner & phosphate remover.  Keeping phosphate levels low can aid in controlling algae (phosphates are a natural food source for algae).

Many pool experts dismiss phosphates almost all together.  PoolSpaGuru's response is: don't go crazy, but if you can remove one more stress point or one more cause to potential water problems, why not take action?  Removing phosphates certainly will not hurt anything. And may prevent a  cumulative affect costing you, the pool owner, time and money.

Nitrogen can also come into your pool from lawn care  products, but more typical, it's a case of sweat (shower before using the pool),  urine (use the facilities before going into the pool) or other types of ammonia  (ammonia is comprised of Nitrogen & Hydrogen - NH4).  If your local water  supplier is using chloramines to sanitize the  water, then large amounts of ammonia & therefore nitrogen are getting into the  water.  Algae loves both nitrogen AND phosphates (phosphorous). 

Here's the typical scenario with Nitrogen. Nitrogen enters the water & combines with oxygen to form Nitrites (NO2). The nitrogen will typically take the oxygen from the HOCl (hypochlorous acid -  the form of chlorine that kills bacteria & algae) thereby causing a Chlorine Demand. You will have a difficult  time maintaining chlorine, algae will thrive, the water will become cloudy, etc.   Once the nitrites have taken on more oxygen & become Nitrates (NO3), they are  there to stay.  The only way to remove Nitrates from the water is to drain  & refill with fresh water that is hopefully not contaminated with Nitrites.  Shocking & oxidizing will help to a certain degree.  Nitrates (NO3) you can live with, Nitrites (NO or NO2) are the problem causers.

With either Phosphates, Nitrites or Nitrates present, as long  as a good, solid chlorine or bromine level is maintained, there normally isn't a  problem.  However, when the chlorine is stressed out due to high bather  loads, parties, rainstorms, etc. or if there is an existing chlorine demand  problem, phosphates & nitrates just feed right into any algae present & the problem worsens significantly. 

Treating the problem:

  1. Maintain good water balance - pH 7.4 - 7.6, total alkalinity 125 - 150 ppm, calcium hardness 200 - 250 ppm.
  2. Maintain a good chlorine or bromine residual in the water.
  3. Shock the pool (BioGuard®  Burn Out 3®, Smart Shock®  &  Oxysheen®  -- especially with bromine--are good products) & add algicide (BioGuard® Back Up 2®, Algae Complete) weekly.
  4. Have a chlorine demand test done twice per season.
  5. Make sure swimmers & bathers shower before using the pool.
  6. If you know or suspect phosphates have been introduced into the  pool, ActivNzyme is a great product that will remove the phosphates (especially orthophosphates) from the pool water, thereby depriving the algae of one of it's significant food sources as well as breakdown other swimmer & environmental waste. 

To Make Your Pool Care Experience Fantastic, add Optimizer Plus®  to create a level of 30 ppm to 50 ppm.  Using Optimizer® Plus will  significantly reduce your Smart Stick® consumption and provide the  wonderful, soft feel that is associated with biguanide treated pools.

Phosphates CAN contribute to algae, but let's not get carried away; really!
Phosphates CAN contribute to algae, but let's not get carried away; really!

Enzymes, scumlines, scaled water features

Enzymes beautify your pool, make water care simpler & more natural

Enzymes are special, naturally occurring (although there do exist man-made and natural enzymes) molecules that "eat" or "digest" organic waste that is not easily filterable or can be readily oxidized. Enzymes are nature's  way to break down many organic compounds.  You'll find enzymes in your own body!  They break down fats and sugars.  Insulin is a kind of enzyme.

Enzymes come in various "types" that are suited for specific jobs.  The enzymes bind to the organic waste and chemically break the waste down.  The final "waste of the waste" is carbon dioxide (CO2) and water.

As you can imagine, turning organic waste in swimming pools into CO2 & water is a great thing!  Those 2  components are then reabsorbed back into the pool or spa water.  Your sanitizer (chlorine, bromine, biguanide, etc.) can concentrate on its  job - killing bacteria. Oxidizers or shocks can do their job - oxidizing contaminants that cause chloramines. Algaecides are not as stressed because algae is not being "fed" by these organic wastes.

Natural Enzymes vs. Synthetic Enzymes -  Whether enzymes are natural or synthetic, they come from the world  around us.  Here's the difference between the two in a broad sense is:  synthetic or man-made enzymes are manufactured or cooked and blended.  They tend to be specific in their "feeding"- they will eat only specific  wastes such as fats and oils. Man-made enzymes tend to be much less stable than natural enzymes.

Natural enzymes are "naturally" formed through the process of fermentation.  Fermentation produces a "broad spectrum" enzyme that is dramatically more stable and able to "eat" a significantly wider range of organic wastes. Natural enzymes such as those found in ActivNzyme will remove all of the following kinds of organics that are often found in swimming pools: human waste, waste fuel oil, deodorants, soaps, bird droppings, sweat, shampoo, body oils, cosmetics, hair spray and other hair treatments, body lotions, pipeline  anti-freeze residue, air borne pollution, tree sap, organic fillers, and more.  The more organic, swimmer and environmental waste that can be "consumed" and eliminated, the less potential problems that you and your pool will face.

Natural enzymes consume the organic wastes that contribute to scum lines that eventually (quickly) become biofilms that are a breeding ground for bacteria and algae.  Build-ups of scum lines are not only visible at the water line, but in the skimmer, pool pipe lines, and even into the filter itself; fouling filter grids, cartridges, and even the sand causing shortened filter runs and media life.


  • Are not water clarifiers.  Clarifiers "clump" together fine particles so that the filter can more easily remove them.
  • Are not detergents - they don't "clean" anything, although they can breakdown or dissolve greases, oils, lotions & other organics. 
  • Don't contain copper. 
  • Are formulated for different environments such as pool water or spa water (cool vs. warm), cold water as in a winterized pool - use the proper enzyme for the correct application.

Enzymes can be used in ALL swimming pools using ANY sanitizing system - chlorine, bromine, Soft Swim®,  Baquacil®.  Enzymes used with ionizers such as Nature2® or Pool Frog®  are a terrific idea because they keep the "beads" in the ionizing canister cleaner by consuming the organic waste that can foul the  canister. 

Regular use of ActivNzyme on a weekly basis will help prevent the organic component of water molds and slime (imagine a pool without pink slime or white water mold!). When you couple ActivNzyme with BioGuard® Optimizer Plus® and AquaFinesse, you have a system that can't be beat. Why? Read more here.

ActivNzyme, the most concentrated Pool enzyme formula available today!
ActivNzyme, the most concentrated Pool enzyme formula available today!