How to Acid Wash Your Plaster Pool Surface

To do so, here is a step-by-step guide:

Turn off the power of your pool filtration system and close the fill valve. Then, attach a sump pump to your drain hose then place it into the deepest part of your swimming pool. After, attach the other end of the drain hose to the sewer clean-out valve then thoroughly drain the pool.
Rinse all the debris from both sides of the pool using a garden hose simultaneously when the water level drop. Scrub the sides of the pool using a pool brush and sweep the debris.
Wear protective clothing such as goggles, overalls if necessary, and a respirator mask. Then, remove the nozzle from the garden hose and keep your pool’s water running whilst cleaning. Add another gallon of water into a large watering can then mix in a gallon of muriatic acid completely. Mix the acid solution respectively. It is important to know that you should never add water to acid, it can trigger a bubbling reaction and can potentially spray your accidentally.
Wet the sides of the pool using your garden hose and work with each side as carefully and thoroughly as possible. Then, carefully pour the acid down by the side of the pool then cover it. Scrub the plaster with an acid brush and let the solution emerge for about 30 seconds.
After, rinse the plaster thoroughly using your garden hose while slowly working your way around to ensure that you rinsed off everything completely. If the pool is still not in a very good condition, repeat the process as you prefer until you reach your desired look.
Then, add 2 pounds of soda ash per gallon of acid water. Meaning, you can use the excess water in the pool and mix in soda ash then use a pool brush to stir or mix. When the acid is thoroughly neutralised, you will notice that the mixture stops bubbling and foaming. When you reach this desired state, place a sump pump in the deepest end of your pool and pump the remaining water into the sewer clean-out valve while rinsing the pool as it drains.