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Step by Step Video:

An Acid Wash is a great way to renew your pool’s overall look without re-plastering it. The acid mix will take off a layer of the plaster and if done correctly with the right mixture, it will also remove 95% of the metal stains and other staining. That is one reason I use Bio-Dex products when I do my Acid Washes. Their products actually do what they say, and you can see the stains coming right off the surface of the pool.


The Acid Wash mix is the most important element of the Acid Wash. Here are the products that you need for a successful acid wash. You will need 31.45% Muriatic Acid mixed with water in a 2 to 1 water to acid mix. Bio-Dex Plaster White ‘n Brite to help thicken up the acid solution so that it runs smoothly down the walls of the pool and to reduce the acid fumes. Bio-Dex AquaDex 50 Stain-Off which helps to remove iron and other metal staining from the surface. If you use this Acid Wash mix you will have great results and the plaster or Pebble Tec will look as good as new!


You can prep the pool to remove some of the calcium build up on the tile with the Bio-Dex Protect-All-Supreme which will require you to raise the water level over the pool tile calcium line, pour in 1 or 2 gallons of the Protect-All-Supreme into the pool and then run the pool for 24-48 hours. In most cases this is probably not something that most customers will opt to do since almost all of the acid washes I have done were in pools that needed to be drained straight away. But it is a part of the treatment and something that you can do as the first step.


Here are the detailed instructions from Bio-Dex on how to do an Acid Wash the Bio-Dex way:


I modified their method because it calls for mixing everything in a 5-gallon bucket and the pouring it down the sides. But I have always done my acid washes using a Water Pot as I find this to be the easiest and most effective method. So in the video I show you the Watering pot mixture also.


Acid Wash Tips:


Always wear protective gear as the fumes and acid are hazardous.


The first thing you should know when you go to do an Acid Wash is that the results cannot be predicted. I can look at a pool now and pretty much predict the outcome. But each pool is different, and results vary.


You only want to Acid Wash a pool if the entire plaster or Pebble Tec is intact. This means no cracks or chips are present. And acid wash will make the chipping even worse so if the surface is full of cracks and holes in the plaster, I would pass on the Acid Wash and move straight to resurfacing it.


You also do not want to drain and Acid Wash a pool if the air temperature is over 90 degrees as the surface can be damaged by the extreme heat exposure. Nor do you want to leave the pool drained for more than one day in hot weather. You also do not want to drain a pool when the water table is high- basically if you have 3-6 inches of rain coming your way, do not drain a pool as it could potentially pop-out. You also don’t want to drain the water into an area around the pool. The ground can absorb the water, and this can also create a situation where the pool can pop-out. This is rare and something you really don’t need to worry about. You of course only want to Acid Wash a plaster of Pebble Tec pool and never acid wash a Fiberglass pool.

If the pool has heavy calcium staining on the surface, organic and metal staining can be trapped under the calcium. You can check for calcium before draining the pool simply by feeling the pool surface.


If it feels very rough like sandpaper, chances are there is a lot of calcium build up on the surface. Before doing the Acid Wash you will need to power sand the pool surface. You can rent a power sander at Home Depot and then sand down the entire pool surface prior to the Acid Wash. During the Acid Wash if you notice the staining is not lifting off, take some sandpaper and rub the area. Then pour the acid mix over the area again. If the stain lifts then you know there is a coat of calcium build-up on the surface and you will have to power sand the entire pool.


Never use just straight acid on the surface. This will etch and damage the surface and will create streaking of the plaster. If the stain is not coming off calcium is probably the issue and not the acid mix.


The basin in the deep end is very critical. I always add Soda Ash to the basin and leave the Sump Pump (Submersible Pump) running so that the acid running off the walls does not pool up and stain the plaster. If this happens, once the pool is filled you will see a discolored ring around the deep end of the pool. So, keep the basin filled with Soda Ash or Baking Soda to neutralize the acid as it runs into the deep end basin and out through the Sump Pump.


If you follow these tips your Acid Wash will turn out great and your pool will have a new lease on life.

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