Has your pool become the black lagoon, not fit for man or beast? There are two basic reasons for undertaking the task of acid washing. One is the black lagoon reason stated above - dark stains in your pool wall that won't come out despite your best cleaning efforts. Acid washing may also be necessary to prepare your pool for resurfacing or simply to enjoy a "like new" finish on your pool once again. It is not used on vinyl liners or above ground pools. The process is pretty involved, and usually requires a professional service to ensure the job is done correctly and safely. However, we will outline the steps here, so you know what to expect if an acid washing is in your future.

Drain your Pool

This step in itself is daunting to many pool owners, but absolutely necessary if you want to get that pool good and clean. As your pool is draining, scoop out all the leaves and debris left on the walls and floor and give your pool a scrubbing it won't soon forget. For a really thorough washing, use tri-sodium phosphate and your brush to get the surface of the pool vessel into pristine condition.

Apply the Acid Wash

The keyword here is acid (muriatic acid, to be exact), so protect yourself properly before you even think about touching the stuff. This means rubber gloves, rubber boots, protective clothing, goggles and a respirator to keep acid fumes away. Once you are properly outfitted, add the acid to water (never water to acid), in equal parts to a watering can or hose sprayer. Wet the walls of your pool first and then spray the acid solution directly onto the wet walls. Work in about a five to 10-foot section at a time, to ensure the walls don't dry out before you add the acid solution to them.

Give the acid a few seconds to do its thing, and then begin scrubbing the walls with an acid brush. You need to make sure the brush you use is specifically designed for this purpose; when in doubt, ask at your pool center. As soon as the acid solution stops bubbling, rinse it off thoroughly with your garden hose. You do not want the acid to dry on the surface of your pool, because it can cause damage. Continue all the way around your pool in this manner; wetting the pool walls, applying and scrubbing the acid solution and then rinsing thoroughly.

Refill the Pool

The sediment left at the bottom of your pool will need to be neutralized before disposing of it. You can do this using soda ash and water before pumping the sediment out of the pool. Estimate about two pounds of soda ash for every gallon of acid solution left. Once you are completely finished with your acid washing, give your swimming pool one more thorough rinse all the way around.

The acid washing process is now complete. You are ready to refill and completely enjoy your all new, pristine swimming pool.