What an acid wash is
You may have seen an acid wash offered on a quote or suggested by a pool service. This page helps you ask about it before you agree to it.
In general terms, an acid wash is a diluted-acid surface treatment used to strip stubborn stains, mineral or calcium deposits, algae residue and surface buildup off the plaster. It is applied either as a stand-alone cleaning treatment or as part of surface prep before resurfacing, usually alongside pressure washing and crack repair.
The exact chemistry, dilution and method belong to the professional doing the job, and they change based on what your surface can handle. Ask a licensed contractor to explain the treatment for your pool specifically in plain words, and do not agree to it until they have.
When an acid wash is used
Whether an acid wash suits your pool depends on what you are seeing and why. Write down what you have noticed on the surface, such as stains, rough patches, buildup or dull areas, and note where each one is. Then ask the contractor to work out the cause before they propose a treatment.
As general background, acid washing is typically used for surface-level problems: mineral and calcium scale from hard water, algae staining, and buildup that sits on top of the plaster rather than inside it. It is not a fix for structural problems — cracking, hollow spots, or a surface that has already lost its bond generally need repair or replastering instead, not a chemical treatment.
Before you agree to anything, ask the contractor these questions.
- What do you think is causing what I am seeing?
- How did you reach that conclusion, and can you show me?
- Is an acid wash the right treatment, or is there a gentler option?
- What result can I realistically expect, and what would still be visible afterward?
- What happens if the treatment does not remove the problem?
A contractor who says an acid wash will fix everything without looking at the pool has not earned your trust. Neither has one who refuses to explain why they would or would not do it.
Risks and limits
Every treatment has trade-offs, and an acid wash is no exception. You should hear about them from the contractor before you sign, not after the work is done.
As general guidance: done correctly by an experienced crew, an acid wash is meant to clean the surface and can improve bonding for a new finish rather than harming it. Done improperly, or repeated too often, it can etch, thin or otherwise damage the plaster. Ask specifically how many times your surface has likely been acid washed before, if that history is known, since a surface can only take so many treatments.
The regional stormwater authority covering Las Vegas has a published rule for exactly this kind of wastewater (written for acid washing masonry, but it’s the applicable local guidance for acid-based cleaning generally): storm drains must be protected from runoff, the treated area gets rinsed with an alkaline soap to neutralize acid residue, the rinse water is collected, neutralized to a pH between 6 and 11, and then pumped to a sanitary sewer clean-out, a sink or toilet, or handled through the local wastewater treatment plant — never discharged to a storm drain. That is on top of the general rule already covered on this site: pool water goes to the sanitary sewer through the clean-out port, never the street, gutters or a storm drain, which Clark County Code prohibits. Ask your contractor to confirm this is how they handle acid-wash wastewater specifically, not just the general pool drain.
Ask about both. On the surface itself, ask whether an acid wash can damage the finish you have, and how they will tell whether your surface can take it. On safety and disposal, ask how the crew protects themselves, your landscaping and your household, and what they do with the used material. If you have pets or children, ask when the pool and the yard are safe to use again. Get the answer in writing rather than as a promise.
Also ask what the contractor will do if they open up the pool and find something unexpected, such as damage they did not see at the visit. You want to know in advance who decides, who pays, and what the process is.
Acid wash or replaster
Sometimes the question is not whether to acid wash but whether to replace the surface instead. Ask the contractor to explain in plain words how the two jobs differ and which one your pool needs.
As a general rule: if the problem is surface-level — staining, scale, algae residue — sitting on an otherwise sound surface, an acid wash is more likely to be enough. If the surface also shows cracking, hollow spots, or roughness spread across the pool, that points toward the bond itself having failed, which an acid wash will not fix. A contractor weighing the two is essentially asking whether the problem sits on top of the plaster or inside it.
The way to decide is to ask for both options in writing. Have the contractor explain what each one fixes and what each one leaves alone. Ask specifically what would change their advice, for example cracks, loose sections or worn areas. Our page on pool replastering covers the replacement option, and pool plaster repair covers a smaller fix you can ask about if the problem is limited to one area.
Be a little wary of a contractor who recommends only one option without explaining why, whether that is an acid wash or a full replaster. The best contractors lay out the choices and tell you which they would pick and why.
How to hire a licensed professional
Hire someone who can show you a current Nevada contractor license. Here is a short process.
- Ask for the license number up front and check it with the state licensing authority. A-10, A-10C or A-10E cover this kind of pool surface work in Nevada; a license limited to C-11 does not.
- Ask for proof of insurance and confirm it is current.
- Ask for references from recent acid wash or resurfacing jobs, and call them.
- Get a written scope that names the treatment, the areas covered, the clean-up and the disposal method.
- Get a written statement of what is not included, such as tile cleaning, repairs or refilling.
- Get any warranty or guarantee on paper. If none is offered, ask why.
- Compare at least two written quotes, line by line.
Prepare for the site visit. Photograph the stains or scale in good light, note when you first saw them, and list anything you have already tried. Tell the contractor about your water source, any chemicals you have added, and whether the pool has been drained or replastered before, if you know. The more the contractor knows, the better their advice.
Pool acid wash cost in Las Vegas
We do not publish a price for an acid wash. What we can say is that the quote should tell you what is included, and whether tile cleaning is part of it or extra. If a quote for an acid wash is much lower or higher than another, the scope is the first place to look.
See our pool resurfacing cost guide for a plain walk through comparing quotes and spotting red flags.
Next steps
If you are unsure whether you need a cleaning or a new surface, the quickest way to find out is to have a licensed contractor look at the pool. Request a quote and we will connect you with a licensed Las Vegas pool contractor. We are a referral service, not a contractor, and any work agreement is between you and the contractor. To see the wider picture before you call, read our pool resurfacing overview.