Guest Column - November 2014
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When Cloudy Water Strikes
Strategies for Handling Water Quality

By Terry Arko

Every aquatic facility manager needs to have crystal clear and inviting swimming pool water at their facility. The reality, however, may be a pool that is hazy, cloudy and flat looking—especially when bather loads increase and temperatures rise. Here are some things to check when the pool goes cloudy.


The first thing to check in a cloudy pool is the filter and circulation system. Make sure that everything is operating correctly. Check to see that the pressure reading on the filter gauge is not reading too high. When the pressure on the filter gauge reaches 10 psi over the normal setting, the filter should be cleaned or backwashed.

Also, check all skimmer suction baskets and the pump basket to make sure they are clean of debris, such as leaves or pine needles. Make sure the pump is operating and there is a good strong flow of water coming back in through the pool return line. If circulation seems dull and the flow of water is not strong, have a pool professional check the pump and filtration system.

Lack of Sanitizer

During the summer, in particular, increased heat and swimming can use chlorine up much faster. If water begins to look cloudy, always do a test of the chlorine levels. Chlorine levels need to be maintained at 1 to 3 ppm.

You should shock the pool weekly in order to clear out excess contaminants and keep the chlorine working properly.

Make sure water is properly balanced. Check pH, total alkalinity, calcium hardness and total dissolved solids. Calcium hardness builds up naturally from source water and certain chemicals. Calcium hardness should be kept at 200 to 400 ppm. Calcium hardness should be tested at least once a year. Total dissolved solids (TDS) is the buildup of all chemicals and solids in the water. High evaporation leads to an increase in dissolved solids. Normal TDS levels are 1000 to 2000 ppm. When TDS is too high, some of the pool water will need to be drained to dilute out the solids. Regular shocking and the use of a water clarifier can help reduce the buildup of solids in pools.

In high-evaporation areas, such as California or Arizona, use a liquid solar cover. This type of product forms a micro-barrier at the pool surface that reduces the evaporation rate, which saves heat, energy and chemicals.

Help the Filter

Pool filters are designed to remove very small particles from water. However, there is a limit to what most filters can remove. For example when dust blows into the pool it can be of a micron size smaller than the filter can remove. As this builds up, the water becomes hazier. Water clarifiers are designed to grab tiny particles and cause them to bunch up together so they can be removed by the filter. The more small particles you are able to remove, the clearer the water will become.

Several clarity products are available to help keep water sparkling clear. You can find natural clarifiers to keep water blue and sparkling. To handle excessive cloudiness, dissolvable pods can be placed in the skimmer basket. After running the pump for 24 hours, the pool will be clear again. For pools with heavy oil buildup from sunscreens, try a product that combines natural clarifier and oil-eating enzyme. And if phosphates are a problem, you can find a three-in-one product that can clarify, stop oils and remove phosphates.

The key is to know your pool's situation, and carefully select the best chemicals to handle your water's unique problems.

Clear water is as simple as these three steps:

  1. Rely on good equipment.
  2. Ensure proper sanitizer and water balance.
  3. Help your filter do its job with the right clarifiers.

Keep these all in check, and your pool will stay blue, clear and sparkling.

Terry Arko has more than 30 years experience in the swimming pool and hot tub industry. He has worked in service, repair, retail sales and chemical manufacturing. He has experience in customer service, sales and product development. His expertise is in the area of swimming pool and hot tub water chemistry. Terry is both a Certified Pool Operator (CPO) and CPO course instructor through the National Swimming Pool Foundation (NSPF). He currently works with SeaKlear Recreational Water a division of Halosource Inc., a company in Bothell, Wash., that creates technologies to make all water better. This includes drinking, environmental and recreational water. Learn more at