How To Acid Wash A Plaster Pool

How to Acid Wash A Plaster Pool With Muriatic Acid & Bio-Dex Plaster White 'N Brite

Hi everyone! Welcome to a Tutor-Time Tuesday! Occasionally we like to educate our customers about certain events that take place in their backyard. Today we will be discussing how to acid wash your pool using 2 specific products. Bio-Dex’s Plaster White and Bright and muriatic acid are two crucial pieces of equipment when preforming an acid wash in a Plaster-style pool. We walk you through all the steps needed as well as how to have a beautiful, finished product! Let's dive in! 

We have all had a pool that just is not getting as clean as it used to be. We have tried upping chemicals a little, we have tried to run the cleaner and skimmer a little longer than before and it is still just not quite clean enough. It is more than likely that you are overdue for an acid wash. Acid Washing is the form of introducing muriatic acid or a similar compound into the plaster or Pebble Tec pool finish to remove stains, deposits, or unwanted particles that may be present in the finish of the pool. 

So, there are a few different methods of acid washing. Which method is right for you?

It is important to note that with both applications of acid washing you will need a sump pump, hose, container or bottle, brush, safety glasses, gloves, and coat as well as acid resistant boots and clothes.

We suggest always asking for a second pair of hands as well such as contacting a pool professional if you are uncomfortable with working with acid or similar chemicals. 

For both methods, we will turn off any power or equipment to the pool, locate the drainage route and drain the pool completely, turn off any water leveler or refills before we get started!

First let us break down the different methods. The first being exclusively using muriatic acid diluted with water. 

We will grab all the required safety equipment, a brush, a bottle, or container to mix, and a gardening hose or source of clean water. We will of course use the A&W method (Acid to Water) to mix and dilute the solution for use. To go into that a little further, it is important to ALWAYS pour or mix acid into existing water and not the other way around. It is also important to note a 30/70 mix is being used for this. 30% Acid and 70% water. If we notice this is not strong enough, we can always add more acid for strength. At this point, we will apply the solution to our plaster or Pebble Tec because this method works for both applications. We suggest pouring the solution onto the surface and then brushing with a pool brush and washing clean with hose water after letting it sit for a few minutes max. In a rinse and repeat fashion. While this process may seem time consuming, it makes for a nice, finished product.

Secondly, we’ll get into Bio-Dex Plaster White 'n Brite, similar to the above method, we’ll grab all the required safety equipment, a brush, bottle or container to mix, and gardening hose or source of clean water as well as our Plaster White N Brite. The Plaster cleaner can be used as a standalone product without the need for dilution. However, the directions suggest mixing into already diluted acid water mix for the best results. Simply add eight ounces of Plaster White ‘n Brite to the diluted acid solution and stir for one minute. Pour the mixed solution along the tile line and allow it to run down the plaster and dwell for at least five minutes. Brush the plaster and tile then hose the product off. You can brush the pool if desired, but it is not needed! One huge added plus is Plaster White N Brite reduces acid fumes and makes the solution thicker and easier to work with. While this product can be added to an acid mixture to use on plaster pools, we do not suggest this product for use with any Pebble Tec finishes. 


After all the surfaces in your pool have been washed with your acid and clean water solution, it will be time to fill the pool back up! One huge reminder when starting the filling process, DO NOT TURN OFF THE WATER FOR ANY REASON! If the water is turned off before the filling process is complete, you may be left with a huge ugly line around the edge of your pool. Because you are using a concentrated acid/water combination it is extremely important to keep to water moving until the pump can be turned on. If for some reason you are worried about overfilling your pool, simply turn the water down to a trickle to keep the water line moving. One other huge key would be to turn your water-leveler on to ensure water will continue flowing into the pool but will turn off once the water line has reached its top point. If for some reason the water does get turned off and the line does occur, your best solution would be to quickly drain the pool again and start the entire acid washing process over again. Though this can be a pain/expensive it will be your best chance at trying to eliminate that line before a resurface is the only option.

We really appreciate you all taking the time to read this blog and we do have a video below with all the instructions in action! Make sure to keep an eye out for many more blogs to come and be sure to subscribe to both our YouTube channel and our newsletter to stay on top of all things pool related!



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