How To Acid Wash A Pool

Is your pool sporting a collection of unsightly stains or patches of discoloration that have been caused by regular use or a build-up of leaves and algae?

If so, your pool will likely benefit from an acid wash, especially if your normal maintenance routine of scrubbing the surface is no longer cutting it.

How To Acid Wash A Pool

Now you may be wondering what acid washing your pool entails and how you should go about performing this task.

We have provided you with all of the answers in our guide below. Continue reading if you would like to find out more. 

What is acid washing?

Acid washing involves the use of a chemical known as muriatic acid. It is applied to the walls and floor of a pool’s previously scrubbed surface before being rinsed off.

The toxicity of this acid makes it effective in removing stubborn stains and debris, ultimately helping to restore the finish of the pool.

Why do pools need to be acid washed?

As we have mentioned, some pools will be prone to an accumulation of stains or some surfaces may begin to appear discolored following years of frequent use.

For example, a pool that has been constructed from plastic may begin to change color following exposure to magnesium.

Whilst it is important to adopt a daily cleaning and maintenance routine for your pool, from time to time you will likely need to use something more powerful rather than simply scrubbing the pool alone. 

When should you acid wash a pool?

Before we delve into the steps involved in acid washing a pool, you must be able to identify the signs that will tell you when it needs to be implemented.

Generally, a pool will require acid washing every 5 to 10 years. Doing it more often can actually inflict damage upon your pool because each time the acid is used, it strips a layer away from the surface.

Wear and tear that has been caused by years of use, stagnation, algae build-up and the development of stains are all situations that may call for an acid wash. 

How to acid wash a pool

First, you will need to drain the water out of your pool. As the water is emptying ensure that you clean any debris that has accumulated and any rubbish that has gathered on the floor of the pool.

If your pool is equipped with an auto-fill function, you will need to make sure that it is turned off before you start to drain it. You can then begin the process of acid washing your pool once it is completely drained. 

As muriatic acid is a chemical that is toxic and highly corrosive you must take precautions and wear the necessary protective gear before using it.

A mask will be needed to protect your respiratory system from the fumes that it emits. You will also need to wear gloves to prevent the acid from burning and irritating your hands.

Failing to wear safety goggles can cause the acid to damage your eyes. Finally, you will need to ensure that you wear clothing that covers and protects your body. 

Next, you will need to fill a watering can or bucket with 1 gallon of water. Then add a gallon of muriatic acid. 

You will then need to saturate the surface of your pool with water. This task is going to be made much easier if you have a hosepipe on hand that you can use. A constant flow of water is required.

The mixture that you have previously made will then need to be poured onto the walls of the pool, starting at the top and focusing on one 10 foot section at a time.

You will likely require the help of a second person because someone will need to be stood in the pool with a hose whilst the other person pours in the mixture.

Leave the acid sitting on the surface of the pool for around 30 seconds. Use a brush to scrub the surface whilst you are waiting for the 30 seconds to pass. 

Use a hose to rinse the section that you have just acid washed. You must make sure that you do this quickly but thoroughly, otherwise, the acid will continue to eat its way into the pool’s surface. 

Repeat these steps until you have four surfaces that have been acid washed. 

Finally, you will need to neutralize the pool. Once you have finished acid washing it you will likely notice that a puddle of foamy residue has collected on the floor of the pool.

You will need to neutralize it to prevent it from damaging the plaster. 

You can neutralize your pool using soda ash. 2 lbs of soda ash is going to be required for every gallon of acid solution that was used.

Apply the soda ash to the puddle and use a pool brush to work it in.

Neutralized water can still be harmful to plants and fish/frogs that may live in your pool, because of this you will need to get rid of the water using a submersible pump. 

Once you have pumped the water out, you will then need to rinse the pool. Repeat the process and then pump the pool for a second time. For assurance that it is completely safe, you may wish to do it once more. 

Final Thoughts

The process of acid washing a pool isn’t overly challenging but a task that will be significantly easier if it is done by two people.

It is advised that you only acid wash your pool during cooler weather because heat will cause the plaster to crack and break. Aside from this, you should avoid acid washing your pool during windy weather.

This is because the acid can be harmful so there is a risk that wind will blow it around the pool or back towards you. It is important to be cautious when working with this acid due to its strength and toxicity.