Out of solution generally describes a substance that is no longer dissolved in swimming pool water, as changing water chemistry can often result in minerals and metals no longer in-solution in the pool water.
What does Out Of Solution mean in pools?
Out of solution, also called a precipitate solid, is a term used to describe a substance present in water, but not dissolved in the water. Combining two or more liquid solutions can produce chemicals or substances that go out of solution, such as adding salts to water intended to break chemical bonds between minerals like calcium.
Precipitate usually appears when swimming pools water reaches a saturation point of a mineral such as calcium or metal such copper or iron. The water can only hold so much dissolved minerals or metals, and any excess substance is left out-of-solution to float freely in the water. This is usually brought about by high calcium hardness and high total dissolved solids.
Having a substance out of solution is generally undesirable in swimming pools, as free-floating minerals can form water scale, and excess metals can stain pool walls and floors. Chemical substances called flocculants and sequestering agents can help remove substances out of solution present in swimming pool water, although their use needs to be strictly followed by manufacturer recommendations. Draining a portion of the swimming pool water is also beneficial, as fresh water replaces the water containing excess solids.