Pool stains: Ultimate guide to diagnosing, eliminating and preventing pool stains
Pool stains are one of the most common problems faced by pool owners. Green, brown or rust, these unsightly marks spoil the water's appearance and can become real headaches if not treated quickly. At Piscine Hippocampe, we have developed this comprehensive guide to help you identify each pool stain, treat it effectively and above all prevent its recurrence.
1. What is a pool stain? Types and origins
Understanding the different types of stains
1.1. Organic stains
Colors : green, brown, reddish
Origins : decomposing leaves, algae (including the dreaded black algae), berries, worms or other organic debris
Characteristics : generally brushable with a stiff-bristled brush, they form where debris stagnates
1.2. Metallic stains (inorganic)
Colors : blue, green, black, rust
Origins :
Copper (heating systems, piping, copper-based algaecides)
Iron (well water, old metal parts)
Manganese , various deposits
Characteristics: insoluble with regular brushing, often mistaken for dirt or pollen
Piscine Hippocampe tip: Don’t try to scrub endlessly: if the stain does not move under the brush, it is very likely a metal stain.
2. Step 1: Precise stain diagnosis
A good diagnosis determines the success of the treatment. Here is how to proceed:
2.1. Water test
Analyze the levels of iron, copper, and manganese using standard test kits.
Note that if metals are already oxidized on surfaces, they may no longer appear in the water analysis.
2.2. Topical test with the "Jack’s Magic Stain ID Kit"
Turn off filtration and let the water remain still around the stain.
Lower the pH and chlorine slightly to optimize the reaction.
Apply each kit packet to the stained area:
Packet 1: removes iron and cobalt
Packet 2: targets copper and scale
Packet 3 (oxidizer): reveals and intensifies stains for better identification
Observe the speed and intensity of the reaction: a rapid release of the stain indicates the metal involved.
Simple alternative: place half a vitamin C tablet (ascorbic acid) on the stain. If the surface immediately discolors, it is an iron stain.
3. Step 2: Protection before treatment
Before removing the stain, the metal ions must be "sequestered" so they do not redeposit. Piscine Hippocampe recommends:
Jack’s Magenta Stuff for iron and scale
Jack’s Blue Stuff for copper
Jack’s Purple Stuff Ideal for salt pools and high TDS waters
Instructions for use :
Dose the sequestrant according to your pool volume.
Distribute evenly around the stained area.
Let act for 15 to 30 minutes before proceeding to the next step.
4. Step 3: Lifting metallic pool stains
You now choose the product revealed by the test and strictly follow the label instructions:
Balance the water, pH and TA (total alkalinity) adjusted according to the manufacturer's instructions.
Disable or Bypass heating to protect the heat exchanger if you are treating a copper stain.
Pour the treatment directly onto the stained area.
Monitor the process: depending on the type of stain, it may disappear in a few seconds or up to 45 seconds.
Renew the application for stubborn stains
5. Step 4: Removal of suspended metals
Once detached, the metals are now suspended in the water. They must be extracted to prevent redeposition:
5.1. Dazzle Filter Enhance
Support : cellulosic fiber to add in the pool skimmer
Action : forms a filtering gel at the top of the sand bed, capturing metals and fine particles
Maintenance : monitor filter pressure, backwash and reapply as needed
5.2. Dazzle Eliminator
Format: small pouch to place in a skimmer basket or pump strainer
Duration: continuous effect for several weeks
Advantage: prolonged purification without constant monitoring
Practical tip: after each treatment, systematically clean your filters to prevent released metals from returning to the water.
6. Step 5: Treatment of organic stains
For stains caused by algae, leaves, or other organic matter:
Chlorine shock: controlled chlorine overdose for 3 to 5 days to disinfect and loosen matter
Intensive brushing: use a stiff brush, focus on corners and joints
Specific enzymes: facilitate the breakdown of organic contaminants
Water balance: maintain stable pH, Total Alkalinity, and chlorine to prevent recurrence
7. Long-term prevention and maintenance
The key to a stain-free pool lies in prevention:
Regular testing: check your water weekly (iron, copper, pH, TA, chlorine, and calcium).
Weekly sequestering: add Stain & Scale 1 & 2 or Jack’s Magenta to neutralize metals.
Weekly sequestering: For weekly maintenance, incorporate Luna technology in chlorine pools and use the powerful Primer from the Pristiva range for saltwater pools. If metal residues remain, Jack’s Magic Magenta is particularly effective.
Improved filter media: consider AFM® ng media, which enhance the capture of particles and metal ions.
Metal source monitoring: well water, heaters, pipes, or algaecides. Replace or treat the source as soon as it is identified.
8. Practical Tips and Quick FAQ
My water is clear, but I have a 2-year-old pool stain
prefer the Jack’s Magic test, even if old, the stain will disappear if the metal is not too deeply embedded.
I don’t see metal in the water test
Go directly to the topical test.
My filter is a cartridge
Dazzle Eliminator in the skimmer, then change or clean the cartridge weekly.
Ideal frequency
analyze and adjust weekly, sequester weekly or monthly depending on the product used.
9. Conclusion
With a methodical five-step approach – Test, Protection, Detachment, Elimination, and Prevention – Piscine Hippocampe guarantees you a sparkling pool, free of stains and worries. Don’t wait for your surfaces to degrade: equip yourself today with the best solutions on the market to bring your pool back to life.
