Pool guide
Pool stains: how to identify them, treat them, and prevent their return
A brown, green, black, or rust-colored stain does not always have the same cause. Before adding a stain remover, you need to determine whether it is an organic deposit, a metal, or an issue related to water balance. A proper diagnosis avoids unnecessary treatments and protects surfaces.
Quick diagnosis
Organic or metal: the first distinction to make
Organic stain
Often caused by leaves, berries, plant debris, or algae.
Clues: green, brown, or reddish; may fade with brushing or after an oxidizing treatment.
Metal stain
Often related to iron, copper, or manganese present in the water or in certain equipment.
Clues: rust, blue-green, black, or brown; generally resists simple brushing.
Method
How to diagnose a pool stain
If the mark comes off easily, an organic origin is more likely.
Well water, heating systems, copper, algaecide, or a recent refill can help guide the diagnosis.
An analysis can help detect certain metals, even though a stain that has already settled may no longer be clearly detectable in the water.
For a persistent stain, a spot test or targeted treatment is more appropriate than blindly treating the entire pool.
Treating an organic stain
Start by removing debris, brushing the area, and checking that the pH and sanitizer level are properly adjusted. Depending on the nature of the stain, an oxidizing treatment can help break down organic residue.
If the stain returns quickly, look for the source: vegetation above the pool, areas with poor circulation, accumulated leaves, or irregular maintenance.
Understanding Jack’s Magic
Which Jack’s Magic product should you use for each type of stain?
The Jack’s Magic line works best when you choose the product based on the actual cause of the stain. Here is the role of the main solutions available from Piscine Hippocampe.
| Product | Main purpose | When to use it |
|---|---|---|
| Solution #1 | Iron and cobalt stains | When the diagnosis points to a rust-colored, brownish stain or one related to these metals. |
| Stain Solution #2 | Copper stains and scale deposits | When the stain is associated with copper or mineral scale. |
| Solution #3 O₂ Safe Shock | Chlorine-free oxidation | As a complementary step when a Jack’s Magic program recommends oxidation with active oxygen. |
| The Blue Stuff | Metal sequestration and stain prevention | After treatment or when a source of metals is known and you want to limit their redeposition. |
| The Magenta Stuff | Phosphate-free sequestrant | For preventing metal stains when a phosphate-free formula is preferred. |
| The Step Stuff | Targeted stain remover for steps | When stains are localized on the steps or in specific areas of the pool. |
Stains mainly on the steps? View Jack’s Magic The Step Stuff.
Solution #1: for iron and cobalt stains
Jack’s Magic Solution #1 is designed to treat stains associated with iron, cobalt, and certain other metal marks. It is particularly relevant when the stain is rust-colored or brownish, or when the water history suggests the presence of iron.
Before treating the entire pool, it is best to confirm the diagnosis with a water analysis and, when possible, a spot test on the stain. View Jack’s Magic Solution #1.
Stain Solution #2: for copper and scale
Stain Solution #2 – Copper & Scale Stuff is intended for stains associated with copper and scale deposits. This type of problem can occur when copper is present in the water, with certain equipment, or when conditions promote mineral precipitation.
Copper stains can sometimes appear blue-green, grayish, or dark. Once again, color alone isn’t enough: the context and water analysis matter. View Stain Solution #2.
The Blue Stuff and The Magenta Stuff: prevent stains from returning
Once the stain has been removed, the job isn’t finished. If metals remain in the water, they can redeposit on surfaces.
The Blue Stuff
High-performance sequestrant designed to help keep metals in solution and reduce the risk of new stains and scale. Discover The Blue Stuff.
The Magenta Stuff
Phosphate-free sequestrant intended to prevent stains and scale when this type of formulation is preferred. Discover The Magenta Stuff.
What about Stain Free?
Stain Free remains another option for certain metallic stains. In this guide, however, we focus on the Jack’s Magic approach to clearly explain the difference between solutions #1, #2, and preventive sequestrants.
Prevention
How to prevent stains from returning
Poorly controlled pH can promote the precipitation of certain metals.
Well water, heating systems, plumbing, or products containing copper can contribute to the problem.
Leaves and organic matter should not remain on the bottom of the pool for long.
When metals are present in the water, a suitable product can help limit their deposits on surfaces. The Blue Stuff or The Magenta Stuff may be considered depending on the chosen strategy.
Frequently asked questions
Pool stains: quick answers
Is a stain that does not come off with brushing necessarily metallic?
Not always, but it is an important clue. Some organic stains or incrustations may also resist removal. A localized test can confirm.
Why doesn’t my water test show any metal?
Some of the metal may have already settled on the surface, reducing what remains measurable in the water.
Can I treat the entire pool without identifying the stain?
It is not recommended. A targeted diagnosis helps avoid unnecessary products and limits the risk of throwing the water balance off.
Unsure of the stain’s origin?
Bring a water sample and, ideally, a clear photo of the stain to the Piscine Hippocampe laboratory. Our team can help you distinguish between an organic, metallic, or water-balance-related source before choosing a treatment.