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Back to basics: Choosing the right clarifier

 By Emily Johnston 

When cloudy water is observed, the first thing to check is the filtration system.
When cloudy water is observed, the first thing to check is the filtration system.

Cleanliness and crystal-blue pool water is always the goal for a pool owner, and specialty retailers and service technicians strive to make sure an inviting pool is always achieved during the hot summer months.

Sometimes, however, events transpire that can create cloudy pool water. Therefore, it is imperative the cause of this water quality problem is properly diagnosed as it is crucial to solving the source of the cloudiness. In most cases, it is a result of improper filtration, insufficient water circulation or flowrate, and poor chemistry. Even early stages of algae growth can cloud the water.

Further, environmental events such as wind or rain storms, nearby plant life, and even swimmers bring undesirable contaminants into the pool water. With adequate sanitization, oxidation, and proper water balance, many issues can be removed or avoided entirely. These tiny particles scatter readily and give water a hazy, murky appearance; however, having the client answer a few key questions can help ensure the right solution is used to solve the problem quickly and get the pool water looking crystal clear again.

Diagnosing the problem

If one notices cloudy pool water, the chemical balance needs to be tested. Low sanitizer residuals or a high pH can be the cause of the problem and it can be easily addressed. In fact, this is a common issue with saltwater pools, which often struggle with an elevated pH. As chlorine is created in the electrolytic cell, sodium hydroxide also forms and drives pH up. As a result, these pools may encounter water-clouding scale from either calcium carbonate or calcium phosphate if the pH is not addressed in a timely manner. Correcting the water chemistry might be sufficient to restore the pristine water but, in some cases, the filter just needs a little help.

When cloudy water is observed, the first thing to check is the filtration system. Some types, such as diatomaceous earth (DE) or cartridge, filter more efficiently than standard silica sand. Maintaining a proper flowrate is one of the most important facets to not only keep water clear, but to be sure sanitizer is adequately circulated throughout the pool.

To check this, service techs must first inspect the filter pressure gauge to be sure it is working properly. Most pool filters will operate normally between 69 and 138 kPa (10 and 20 psi); therefore, it is important to verify it does not rise higher than 69 kPa (10 psi) above the normal operating pressure. If the pressure gauge is working properly, a service tech should place their hand in front of the pool return to feel the water pressure. If it feels weak, it is a good sign the filter should be inspected.

Something as simple as replacing or cleaning the filter media might be enough to re-establish the proper flowrate. If the issue does not appear to be related to a soiled or improperly working filter, it might just be the contaminants are too small for the sand, cartridge, or DE filter media to capture and, as a result, they keep getting circulated through the water. In the event of a cracked lateral or damaged filter manifold, filter media will recirculate back out and deposit onto the pool floor.

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