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Acid wash pool without draining

IMPORTANT – We can remove stains without the need to acid wash your pool or drain the water.  Remember, acid washing a pool surface is not ‘stain removal’ it is surface removal.  Acid washing works because it uses strong acids to dissolve the smooth outer layer of your pool surface!   This is why many pool owners lament that the acid wash process has left their pool surface feeling rough, blotchy and streaky.

Why pool shops suggest acid washing?

  • They don’t know what the stain is
  • You will need to buy lots of chemicals when the pool is refilled
  • Shops make about $500 profit on an acid wash
  • It often works but does not prevent the stains from returning

Acid washing hurts pools

“Acid washing will reduce the life of your pool surface and also make it more coarse than before.  This is because it dissolves the cement in between the pebbles. Aside from this, the process of draining and refilling the pool can lead to surface cracking.”

Acid Washing pool

Acid washing pool

Pool shops suggest acid washing because they sometimes lack the experience and don’t have the chemical knowledge to remove serious staining any other way. Because of this, they will suggest to acid wash (or even a new interior) when it is not required. Our treatments chemically remove the stains without draining or acid washing the pool.

Acid washing – the risks

If an acid wash is done badly the streaks from the flow of toxic acid can permanently etch and discolour parts of the pool surface. Once these streaks appear, there is no way of removing them because the cement is permanently dissolved. Therefore, it is very important to know exactly what you are doing and be very careful when acid washing a pool. Remember, acid washing is not ‘stain removal’, it works by using strong acids that etch and dissolve the smooth outer layer of your pool surface!  The stains are removed because the cement surface of the pool is dissolved during the acid wash. 

Acid washing can be an effective way of removing pool stains but it should only be done if absolutely necessary. Also, we understand that there are situations where there is no other choice. For examples, pools that have been abandoned for several years and have a thick layer of sediment at the bottom should be drained and acid washed.  However, if your pool is left empty for an extended period, the pool surface most likely will de-laminate (or separate) from the structure of the pool – particularly if your pool interior is over 10 years old. So please refill as soon as you can because many pools are damaged by exposure to sunlight and temperature differences.

Acid Washing 3

Acid washing swimming pool

Aside from treatment costs, an acid wash can be inconvenient and expensive. For example, an acid wash alone costs between $850-$4,000 depending on the size of your pool.  Also the prices does change depending on the severity of the stains. Importantly, this price does not include the tap water needed to refill the pool.  This is normally around $185 for 50,000 Litres of water from most city councils. Finally, there is the additional cost of the salt, pool acid, sunscreen and buffer to re-balance your pool water after it is refilled.

Remember, be careful with people who advertise cheap acid wash prices.  In some cases, these unethical contractors will approach you for more money half way through the wash if the stains are not releasing easily. They will argue that extra time and materials are needed to remove the stains. For example, we had one client pay over $3,500 for an acid wash when the actual price they agreed on was less than $900. This scenario can be a very stressful situation for pool owners.


We’re so confident that our products are as powerful as an acid wash that we guarantee it!  So, if our treatment doesn’t remove the stains and an acid wash does, then we refund all your money  – no questions asked.

Acid wash pebblecrete pool

Acid washing is a very aggressive cleaning process that involves completely draining your pool and then pouring or spraying a very strong mixture (often undiluted) of hydrochloric or acid and water on the walls and floor of your pool. This process is sometimes repeated several times to remove stains. After this process is complete your pool is then filled with water once again.

Most pool interiors such as pebble, glass bead or Quartz are not designed to be acid washed more than once or twice over the life of the pool.  This is because this process etches (eats away) the interior and reduces the overall thickness of the pool surface. Often, those who have already acid washed their pool have told us that since their acid wash that the interior now feels rough. This happens because the cement that is normally between the individual pebbles or beads is eaten away by the acid leaving the pebbles more exposed.  This also means that there are ‘pits’ created in the surface that catch and retain dirt and algae.  Remember your pool’s cement interior is a very thin veneer that is often only 3-7mm thick. Therefore if acid washing is not done correctly it can permanently damage the pool and make future cleaning much harder.

The importance of contractor insurance

If you must acid wash your pool then we strongly suggest choosing a reputable contractor who has current liability insurance. This is because very occasionally, when the water is drained, the sides of the pool can buckle, crack  or lift out of the ground. Remember, the damage from uplift damage is not repairable.  So, to help prevent this, most pools have a hydro static valve which releases any water pressure under the pool.  However, in older pools, these valves can seize up which means the water pressure under the pool becomes very high. In these situations, pool uplift is a strong possibility when the water is drained.  When this uplift occurs the pool is irreparable and an entirely new pool structure is required as you simply cannot push the pool back down. Therefore, you will require your contractors insurance to build an entirely new pool should this happen to you.

Pool lifting out of ground
After being drained for an acid wash the hydrostatic pressure pushed this concrete pool out of the ground during refilling

Acid washing your pool – final thoughts

Remember that in some cases, acid washing will not remove pool staining and this leaves clients furious.  This is because many people mistakenly believe that acid washing is a ‘cure all’ for swimming pool stains.  The truth is it is not.  We have removed many stains from pools that have already been acid washed in the past.

You can speak to a stain specialist about your pool today. There is no cost or obligation and we are happy to look at pictures and talk with you before we send a kit or visit. Email pictures to or call us on 0416 927 837.

Our Company Credentials

SPASA members for complete peace of mind.


Certified technicians all with at least 7 years experience.

NSPF Certified The Pool Stain Removers

Approved contractors for commercial and public pools.

EBIX accredited

We carry $5 million in insurance for your protection.

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