There are several reasons to acid wash a swimming pool. Most people call when the pool plaster is looking dirty or the pool has turned green. If this is the case, we do a thorough acid wash which includes:
- we drain the pool with a submersible pump,
- we mix water, acid and a special additive to a pour bucket and pour on the plaster
- we scrub the plaster with a special acid wash brush.
- After the plaster is clean, we rinse the plaster with water.
A proper acid wash can remove algae, dirt, metal stains, light calcium and many more stains that can get on the plaster. We always wear eye protection and a proper mask to protect our lungs.
The another reason to acid wash is for routine care of the plaster. Every two to three years it's a good idea to drain a pool and do a light acid wash. This will help keep calcium and salt from attaching itself to the plaster. Most of the pools we drain we see calcium damage. Calcium damage happens when there is too much cheap bagged shock poured in the pool. The cheap shock is called calcium hypochlorite. It's usually the first thing a pool store will hand you when you tell them you have an algae problem. A lot of times when a customer calls me about water quality issues or stains in the pool I will see an empty case of shock. What happens is the quick shock might help you short term, but the long term effect is higher hardness readings in the pool. I recommend using a quality shock such as trichlor. If you ask your local pool store for it by name I'm sure they will know what your talking about. The trichlor is way more expensive, but well worth the extra expense. To help keep the calcium in check, make sure you keep the pH level in a proper range in your pool. A light acid wash will work much better done every two years or so. If you wait too long the calcium penetrates into the plaster and will start to damage the plaster.
Another problem were seeing is salt damage. With people converting their pool over to salt water, they don't realize there is down side to this. The salt builds up all over the tile, the plaster, and the filter elements. We use a lot more acid on a salt water pools to keep the pH down than on a traditional set up. An acid wash every couple of years can really help keep calcium and salt from damaging your pools underwater surface areas.