Hard pool water is….well, HARD to avoid. Tap water has several minerals in it including calcium and magnesium. As pool water evaporates, pure water escapes while the dissolved solids like calcium and magnesium stay dissolved in the pool water. These minerals grow in parts per million over time in the pool water eventually creating hard pool water. Put simply, you are adding hardness to pool water every time you add tap water to your pool or spa.

Pool water needs some hardness, so this is not a bad thing. If the pool water does not have enough calcium, it will strip it out from the plaster or aggragate of pool surface. Perfect water chemistry is a balance with a few constants, so we need a plan.

Chemicals And  Swimmers Add To Hard Pool Water

Everything that makes contact with your pool water will leave dissolved solids. From bodies to leaves to chemicals to conditioner, etc. etc. At Pool Heaven, we have a special chemical plan that helps us elongate the life of your pool, but you should count on draining and refilling your pool water or using pool water recycling every 5 to 10 years.

High pool conditioner is very hard to avoid as chlorine tabs are the most convenient source of chlorination in the summer. They are slow dissolving, so we don’t have the spikes and drops of chlorine levels like adding instant liquid chlorine. The problem with chlorine tabs is they have conditioner in them, so over time, chlorine tabs will raise your pool conditioner level. You can read about high pool conditioner here, but one of our policies is to add liquid chlorine as much as possible.

You might say that we are battling several fronts against total dissolved solids, but it’s much easier to just know to replace your hard pool water every 5 to 10 years. Hard pool water will allow for fall out and scaling. Due to the high saturation of minerals in the pool water, calcium and other minerals will fallout and stain the pool tile, pool surface, deck, boulders, and/or all other objects making constant contact with the pool water.

Tile scaling is unavoidable in some pools with quick evaporation rates especially in salt water pools and pools with darker colored tile. Pool water will evaporate on the pool tile and deposit white calcium which leaves a white ring around the pool. Read here about pool tile cleaning to fix this issue.

Think of a table where you leave a cold glass of water which leaves a condensation ring on the table. The water evaporates, but the minerals remain and deposit on the table leaving a visible ring. 

Salt water pools have high total dissolved solids from the get go and you can read everything about salt water pools here. Most salt water systems require at least 3,000 ppm salinity while pool water is considered high in total dissolved solids when over 2,000 ppm. You should expect scaling and white deposits with salt pools.

Have A Plan To Battle Hard Pool Water

In addition to white scaling and deposits, hard pool water will decrease the efficiency of chlorine in the pool water. We will need higher levels of chlorine to kill bacteria and algae in the pool water which will create aggressive pool water and/or an algae prone swimming pool. We do our best to fight hard pool water, but every 5 to 10 years, we should expect to drain and refill or use pool water recycling.

At Pool Heaven, we customize pool water chemistry plans for each swimming pool depending on the age and level of high total dissolved solids in the pool. For some pools, the only options is to switch to liquid chlorine only until we drain and refill or use pool water recycling. Our goal is to provide the best pool experience possible for our customers, so they can save money and enjoy their swimming pools and spas.