PC102: CHLORINE DEMANDSMART START Pool School

WHAT IS A CHLORINE DEMAND?

➤ A chlorine demand is the consistent inability to hold free chlorine in a pool.

➤ Oftentimes, this presents as a need to shock much more frequently; chlorine applied one day will have completely dissipated by the next, regardless of water chemistry.

➤ It is important to test your water with The Pool & Spa House to rule out other causes of fast chlorine consumption:

➤ Low pH

➤ Low stabilizer

WHAT CAUSES CHLORINE DEMAND?

➤ A chlorine demand is the result of an overload of contaminants in the water. Some common contaminants found in pools:

➤ Bacteria

➤ Algae

➤ Urine

➤ Sweat

➤ Makeup

➤ Fertilizer

➤ Animal waste

➤ Rain

➤ Plant material

➤ Pollution

In short, everything causes a chlorine demand if enough is present!

MY POOL IS CLEAR!

➤ A pool presenting with chlorine demand may appear clear or cloudy; often there is little to no correlation between water clarity and demand severity.

➤ A clear pool with no free chlorine is not suitable to swim; without free chlorine present in the water, there is no way to kill bacteria.

HOW DO I GET RID OF A CHLORINE DEMAND?

➤ A chlorine demand will almost always require a large dose of chlorine to “break” the demand.

➤ The only way to figure out exactly how much chlorine to apply is to bring a water sample to The Pool & Spa House and ask your water care specialist to run a chlorine demand test.

➤ The chlorine demand test will compare your water to a control sample and calculate exactly how much chlorine needs to be applied to break the demand.

➤ Note that this test cannot be run if your pool has any free chlorine; your free chlorine must be 0ppm!

HOW DO I GET RID OF A CHLORINE DEMAND?

➤ For pools with particularly severe demands, we will recommend partial drains and refills to reduce the demand, making treatment easier and more cost-effective.

➤ A partial drain and refill involves lowering the water level to just below the skimmer and refilling. We will usually recommend 3-4 partial drains and refills to reduce demand.

➤ Once partial drains and refills are complete, your water will need to be tested again for demand; do not add chlorine before retesting. Small additions of chlorine can make the demand worse.

HOW TO TREAT

➤ Specific instructions will be provided for your pool and situation to treat for demand. It is important to follow all steps in the order provided, adhering to recommended wait and testing times.

➤ Regardless of treatment, frequent testing to check free chlorine will be required. A demand is considered “broken” when your pool holds 10ppm of free chlorine for 72 hours.

➤ The key to preventing a chlorine demand from occurring is by following the care system most appropriate to your pool. Be sure to test chlorine levels at least twice a week, especially during the heat of the summer.

➤ During days of hot weather, heavy usage, or rainfall, additional doses of shock and algicide can destroy contaminants before they have a chance to build up.

➤ Make sure your filter media is clean and not too old; this will ensure that treatment and maintenance are as easy as possible.

THANK YOU!Click NEXT to continue!