The Benefits of Acid Washing Your Pool: When You Should Do It and Why
Over time, every pool begins to show signs of wear—stains, algae marks, calcium deposits, or rough, discoloured surfaces. While regular cleaning and maintenance keep your water healthy, sometimes your pool needs something a little stronger. That’s where an acid wash comes in.
Acid washing is a specialised deep-cleaning process designed to restore the look of your pool interior and remove stubborn stains that normal cleaning simply can’t handle. Here’s everything you need to know about what it is, why it’s beneficial, and when it’s the right time to do it.
What Is an Acid Wash?
An acid wash is a professional cleaning method that uses a carefully diluted mix of muriatic acid and water to remove a thin layer of the pool’s interior surface—usually concrete, pebblecrete, or plaster.
It eliminates:
Algae stains
Calcium and mineral deposits
Discolouration
Rust spots
Scale buildup
Organic stains from leaves, dirt, and debris
It’s essentially a reset button for your pool’s appearance.
Benefits of Acid Washing Your Pool
1. Removes Deep and Persistent Stains
If your pool has had repeated algae problems or has been neglected for a period of time, stains can soak into the surface. These stains often cannot be scrubbed off with normal cleaning.
An acid wash removes the top stained layer, revealing clean, fresh surface beneath.
2. Restores Your Pool’s Original Colour
Discoloured or blotchy pool surfaces can make the water look murky—even when the chemistry is perfect. Acid washing brightens and restores the colour of the interior, improving both the look of the pool and the clarity of the water.
3. Eliminates Algae at Its Source
Algae can burrow into porous surfaces like plaster or pebblecrete. Even when the water looks clean, microscopic algae can remain lodged in the walls, ready to bloom again.
An acid wash removes these embedded algae spores, helping prevent recurring green or black algae outbreaks.
4. Removes Calcium Scale and Rough Build-Up
Calcium deposits create rough, sharp, or chalky patches on the walls and floor. These can be uncomfortable for swimmers and difficult to remove with brushing alone.
Acid dissolves mineral scale and smooths the surface, making cleaning easier and the pool more comfortable to swim in.
5. Improves Overall Water Quality
After an acid wash, the fresh, clean surface is easier to maintain.
A smoother interior:
resists algae growth
holds less dirt
requires fewer chemicals
allows your filtration system to work more efficiently
This often leads to clearer water and lower long-term maintenance costs.
When Should You Acid Wash Your Pool?
Acid washing is not something that should be done frequently—it removes a thin layer of the pool’s interior, so it’s best reserved for when it’s truly needed.
Here’s when to consider it:
1. When Your Pool Is Extremely Green or Black
If your pool has been left untreated for a long time and has turned dark green, mustard, or black, the algae may have deeply stained the interior. In these cases, shock chlorination typically isn’t enough.
2. When Stains Won’t Come Off With Regular Cleaning
If brushing, vacuuming, and chemical treatments haven’t made a difference, the stains may be too deep for surface-level cleaning.
3. When You Notice Heavy Calcium Scale or Mineral Build-Up
Large patches of white, rough, or crusty scale are a clear sign that an acid wash may be needed.
4. After Major Equipment Failure
If your pump or chlorinator stops working for an extended period, water quality can quickly deteriorate. Sometimes the staining left behind needs more than a standard cleanup.
5. Every 5–7 Years as Part of Long-Term Maintenance
Most concrete, pebblecrete, or plaster pools benefit from an acid wash every 5 to 7 years, depending on water balance and care.
Why You Shouldn’t DIY an Acid Wash
Acid washing involves strong chemicals, specialised equipment, and proper drainage procedures.
When done incorrectly, it can:
damage your pool interior
cause uneven surface texture
lead to safety hazards
void warranties
It’s a job best left to trained professionals who know how to safely apply acid, neutralise the surface, and protect the surrounding areas.
The Bottom Line: Bring Your Pool Back to Life
An acid wash is one of the most effective ways to transform a tired, stained, or algae-ridden pool back into a bright, fresh, and inviting backyard centrepiece. When done at the right time—and by the right professionals—it can dramatically improve the look, feel, and health of your pool.