ServicesAcid Washes
Acid Washes in Phoenix
A pool acid wash dissolves the stained top layer of plaster so the cleaner material beneath shows through. Before anything is drained, we check your finish and tell you what the wash will and will not fix. Then we drain, wash, neutralize and refill in a set order.
What an Acid Wash Actually Does
Most plaster pools are finished with white cement blended with crushed marble or quartz aggregate. That surface is porous, and over the years dissolved minerals, metals and organic stains soak into it. Brushing and water chemistry only reach the top. An acid wash puts diluted muriatic acid on the drained shell to eat away that outer skin, and the discoloration leaves with it. The material underneath is lighter and cleaner.
That is also the catch. Every wash takes plaster away, and plaster does not grow back. A finish in good shape can handle a wash every several years. A finish that is already thin, rough or flaking will look worse after one. That is why we inspect before we quote, and why some pools are better served by stain treatment or tile work instead.
What Our Acid Wash Includes
Finish inspection
Before quoting, we gauge how much plaster is left around the steps and in the corners, tap for hollow spots that signal delamination, and feel for rough wear. We also figure out what is causing the stain, since metal, organic and calcium marks each react to acid in their own way.
Full drain
We pump the pool down with a submersible pump and send the water where local discharge rules allow. If you only need the drain and fresh water, our pool drain and refill service covers that on its own.
Controlled acid application
We work the diluted acid onto the walls and floor in sections with a brush and sprayer, then rinse each section before the acid etches too far. Heavier stains get a second pass only where needed.
Neutralizing and cleanup
Spent acid pools at the deep end. We neutralize it with soda ash, then pump out the slurry so no active acid sits on the plaster or reaches your yard.
Refill and start-up chemistry
Fresh plaster surface is reactive for the first days. We balance pH, alkalinity and calcium hardness as the pool fills so the new surface does not start pulling scale or etching right away.
Signs Your Pool Is Ready for an Acid Wash
Gray or brown staining
Broad discoloration that brushing and chlorine will not lift usually means stains have settled into the plaster surface, not just onto it.
Black or green shadows after algae
After a serious algae bloom, the water can be clear while the plaster stays mottled. A wash often follows a green to clean recovery for exactly this reason.
White, crusty scale on the floor
Hard fill water leaves calcium deposits that build up into a chalky crust. Light scale on the waterline is a job for calcium removal and tile cleaning; scale across the whole surface calls for a wash.
Water is due to be replaced anyway
When total dissolved solids climb high enough that you need fresh water, combining the drain with a wash avoids emptying the pool twice.
Rough feel underfoot
Scale and mineral buildup make plaster feel like sandpaper. Removing that layer usually brings back a smoother surface, as long as enough plaster remains.
How the Day Goes
- 1
Confirm the plan on site
We walk the pool with you, point out the stains we expect to remove and any we do not, and confirm the finish can take a wash.
- 2
Drain and prep
We shut off the pump and heater at the breaker, drain the pool and clear debris from the floor. We do not leave a pool sitting empty longer than the job needs, since bare plaster in hot sun can crack and dry out.
- 3
Wash and rinse in sections
Acid goes on top to bottom, a section at a time, with an immediate rinse. Timing matters more than strength here; leaving acid on too long etches the plaster unevenly.
- 4
Neutralize, refill, balance
We neutralize and remove the acid water, start the refill, then bring the chemistry into range so the fresh surface stays clean.
What Moves the Price of an Acid Wash
We quote an acid wash after we have seen the pool in person, and you get the price in writing. Three things carry most of the weight: the amount of plaster to treat, the kind of staining on it and the route the drain water takes out of your yard. Here is how each one plays in.
- Pool size and depth
- A larger, deeper shell has more plaster to cover, so it takes more muriatic acid and more hours on the brush. It also holds more water, which lengthens both the drain and the refill.
- Stain type and severity
- Light organic discoloration usually comes off in one application. Iron or copper stains and heavy calcium crust often call for spot treatment, a second pass in the worst areas, or a separate method before the wash starts.
- Finish type
- Plain white plaster is the most direct job. Pebble and quartz finishes get a weaker mix and shorter contact time, so the acid cleans the surface without loosening the aggregate.
- Drain access
- How far the hose has to run to the discharge point, and how it has to be routed around your home, changes how long setup takes.
Acid Wash Questions
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How many times can a pool be acid washed?
It depends on how thick the plaster was to begin with and how aggressive past washes were. Each wash removes a thin layer, so there is a limit. We check thickness at the steps and edges before we recommend one, and if your plaster is near the end of its life, we will say so before anything is drained.
Will an acid wash make my pool look new?
It will make sound plaster much lighter and cleaner. It will not fix chips, cracks, hollow spots or rough areas where the plaster is wearing through. We point those out during the inspection so your expectations match the result.
Can you acid wash a pebble or vinyl pool?
Pebble and quartz finishes can be washed with a milder mix and shorter contact time. Vinyl liners and fiberglass shells should not be acid washed at all, because the acid damages those materials. For those surfaces we would talk through other cleaning options.
Is the acid safe for my yard and plants?
Diluted muriatic acid is strong, which is why we neutralize it with soda ash in the pool before pumping it out. We also rinse decking near the work area. Nothing active leaves the pool shell.
How do I keep the stains from coming back?
Stable chemistry is the main defense, especially calcium hardness and pH with hard fill water. Our weekly pool cleaning includes chemicals in the monthly price and comes with no contract, and your first month of weekly service is free.
Find Out If Your Plaster Can Take a Wash
We will look at your finish, name the stains and tell you plainly whether an acid wash is the right fix. The quote costs you nothing.