Just as rain clouds can put a damper on a pool day, so can murky and cloudy pool water. Not only is cloudy pool water unappealing, but it’s also a sign of harmful bacteria and impurities that are unsafe to swim in. Thankfully, with the right advanced oxidation process (AOP) pool and spa sanitation system, you can enjoy fresh, sparkling and crystal-clear pool water.
AOP pool and spa sanitation systems offer a healthy, low-chlorine alternative to traditional chlorine, salt and other chemicals. While there are two types of AOP methods, they both use hydroxyl radicals that destroy unwanted contaminants, bacteria and chlorine-resistant viruses.
There are two top AOP sanitation options available that can clear up cloudy water: Hydroxyl-Based AOP and Ozone + UV AOP pool and spa systems. But which one can make your pool or spa effortlessly crystal clear? We put them both to the test to find out.
The Challenge: Cloudy Pool & Spa Water
Cloudy water is a common issue for pool and spa owners. In short, cloudy pool or spa water is a sign of impurities that can harm both your water quality and health. However, fixing pool or spa cloudiness can be tricky because there are many possible causes. Without AOP, it’s difficult to pinpoint the exact culprit. Some common causes include:
- Inadequate oxidation and sanitation
- High swimmer bather load (many people using the pool)
- Inadequate circulation or filtration
- Imbalanced pH levels
- Presence of algae or bacteria
- Weather conditions (e.g., heavy rain, wind-blown debris)
- Increased levels of dissolved solids or minerals
- Excessive alkalinity levels
- High calcium levels
Additionally, cloudy pool water reduces visibility in pools and spas, increasing the risk of accidents. To tackle this challenge, alternative sanitation outside traditional chlorine and salt pool systems are needed. Efficient alternative methods, like AOP pool and spa systems, offer a promising solution for restoring water clarity and ensuring a safe swimming environment.
The Solution: AOP Pool & Spa Systems
As health, wellness and sustainability concerns grow, there are plenty of alternative pool and spa sanitizers. However, AOP pool and spa sanitation systems are a new innovation that stands out. The right AOP method should check off boxes for: health, sustainability and, of course, water clarity.
What Are AOP Pool & Spa Systems?
AOP pool and spa sanitation systems utilize an “advanced oxidation process” that can be done with two different AOP technologies. However, both of these technologies use hydroxyl radicals. These hydroxyl radicals effectively destroy or ‘oxidize’ cloudy-causing impurities, bacteria, contaminants and chlorine-resistant viruses that chlorine and salt tackle can’t alone.
How Do AOP Pool & Spa Systems Work?
These radicals are the strongest ‘oxidizers’ available for recreational water treatment. If you’re not familiar with how an ‘oxidizer’ works, picture those TV commercials for home cleaning products that erase tough stains on clothing instantly. That’s ‘oxidation’ at work. Similar to ‘oxidizing’ stains on clothes, AOP restores water clarity.
By taking the sanitation load off the chlorine or salt pool system, AOP’s hydroxyl radicals therefore lowers the need for additional chlorine or salt use. But unlike chlorine or salt, hydroxyl radicals last micro to milliseconds in plumbing, never reaching the pool, spa, swimmer or surfaces. This allows swimmers to enjoy clear water with less irritation, chemical exposure and environmental impact. Overall, AOP systems are favored over outdated sanitizers because they need less chemicals to give better protection than chlorine, salt and other chemicals can alone.
2 Top Types of AOP Pool & Spa Systems
Remember, while Hydroxyl-Based AOP and ozone + UV are both “AOP”, they’re two physically-different technologies. These AOPs vary in installation, maintenance time, treatment capacities and overall results. Let’s look at the two top AOP methods.
1. Hydroxyl-Based AOP Pool & Spa Systems
Unlike other AOP pool systems, patented Hydroxyl-Based AOP uses a science-backed process inspired by the natural way hydroxyl radicals clean the air we breathe. Hydroxyl-Based AOP pool systems pull in surrounding air we breathe and treat it. Inside the AOP system, those oxygen molecules are split (from O2 to O1). Then, Atomic oxygen (O1) is air-injected into plumbing and creates hydroxyl radicals by a reaction to pool water.
Key Features:
- Uses a patented, one-of-a-kind AOP technology
- System treats air, not water
- A dry system, with air flowing through
- Available in one form from the patent-holding manufacturer
- Proven on pools, spas and waterparks
2. Ozone+UV AOP Pool & Spa Systems
As a more common “AOP” method, Ozone + UV AOP pool systems use a two-part process that makes hydroxyl radicals in a round-about fashion. Ozone and UV pool treatment technologies have been used separately for decades, but recently have been used together to make hydroxyl radicals. First the ozone + UV AOP pool system injects ozone (O3) gas into pool plumbing. Then, the ozone + UV AOP pool system passes water over a UV lamp. Water flowing through systems can cause wear-and-tear, which can lead to repairs.
Key Features:
- Uses an ozone and UV technologies
- System treats air via ozone and water via UV
- A wet system, with water flowing through
- Available in multiple forms from different manufacturers
- Primarily used on home pools and spas
To see how well these two AOP methods clear pool and spa water, we put them to the test and monitored results.
The Results
Both the Clear Comfort AOP and Ozone + UV AOP systems were tested in identical conditions and installed by manufacturer instructions. To compare the two AOP sanitation methods for large swimming pools, a controlled spa, or hot tub, offered an ideal setting to repeatedly monitor a concentrated simulation of contaminated pool water. Testing was done in a non-chlorinated, outdoor and covered 500-gallon spa. Before each test, filters were cleaned, surfaces scrubbed and the spa water filled with fresh tap water, heated to 104°F for 24 hours. Additionally, the circulation pump ran during testing.
Using this simulated setup, both the Hydroxyl-Based AOP and Ozone + UV AOP systems were monitored for performance. Testing used Nephelometric Turbidity Units (NTU) to measure particles in the water. In short, a lower NTU means clearer water.
After the 24-hour period, testing confirmed the recovery of the baseline NTU readings:
- Hydroxyl-Based AOP System: 86.2% Water Clarity Recovery
- Ozone + UV AOP System: 43% Water Clarity Recovery
While testing results found that both AOP methods helped water clarity, Hydroxyl-Based AOP had twice the oxidation power than Ozone + UV AOP. Results confirmed that Hydroxyl-Based AOP delivered cleaner, clearer water more effectively and faster than Ozone + UV AOP.
Key Takeaways
With multiple potential factors that cause cloudy pool or spa water, identifying the culprit without AOP can be challenging. AOP systems offer a modern way to maintain clean, clear pool and spa water. Overall, AOP pool and spa systems improve water quality with less need for chlorine, salt and other chemicals. With less toxic chemical reliance without compromising protection, AOP is an ideal choice for health- and environmentally-conscious pool and spa owners.
When comparing Hydroxyl-Based AOP and Ozone + UV AOP, Hydroxyl-Based AOP consistently delivers cleaner, clearer water due to its superior oxidation power. If you want the best, healthiest and easiest sanitation that keeps pool and spa water crystal clear, Hydroxyl-Based AOP is the clear choice.
Want to see the full Water Clarity AOP Comparison Case Study? To download it now, click here.
