Answer: Cyanuric acid shouldn't be at Zero for an outdoor swimming pool because chlorine will deplete faster in hot and humid weather, leading to cloudy water. If your FC is at normal level of 3ppm, raise Cyanuric acid level to 40 ppm and you will reduce chloramine levels that make your water appear cloudy.
1. Low Free Chlorine(FC) Low FC is the most common cause of cloudy/milky/murky/dull pool water. To clear a cloudy pool caused by low FC levels, you need to shock your pool by adding liquid chlorine to raise your FC to recommended level depending on the Cyanuric acid(chlorine stabilizer) level in your water.
Cyanuric acid (CYA), also known as chlorine stabilizer or pool conditioner, is a critical chemical that stabilizes the chlorine in your pool. Without cyanuric acid, your chlorine will quickly break down under the sun's ultraviolet rays.
How long does it take for a cloudy pool to clear? Depending on how cloudy your water is, it may take 2-3 days for your water to clear. If you're using a clarifier, you'll need to run your filter 24/7, keep your water chemistry balanced, and add the proper amount of water clarifier every other day until it's clear.
It's usually just a temporary reaction as the sanitizer works its magic, and doesn't always indicate a problem. But if the cloudy water persists long after you've shocked the pool, you're likely having an issue with water balance, circulation, or filtration.
Cloudy water may still be safe to swim in, but if the chemicals are not balanced, then swimmers can experience red eyes, irritated skin, and rashes. If the cause is environmental factors, it can usually be cleared up with a clarifier and regular cleaning.
If there is a problem with the chlorine, pH or other chemical levels in your pool, adjusting those levels can be enough to correct the cloudiness. For example, if your pool water is too basic, you can add hydrochloric acid or sodium hydrogen sulfate to lower the pH.
Rapid pH Change
It drastically raises the pH in the water around it, which leads to clouding. This explains why the cloudiness does not happen all at once, rather the process creates a cloudy plume that slowly expands across the pool.
The problem with low cyanuric acid is chlorine degrades quickly in the presence of sunlight. Chlorine is rendered completely ineffective within a few hours of sun exposure. If you didn't have cyanuric acid in your pool or it was low, you'll find that you need to add a lot more chlorine to have effective sanitization.
Cyanuric Acid Facts
It serves as a protection shield for chlorine against sunlight. The Sun's ultraviolet rays degrade chlorine very quickly, creating a problem for outdoor pools. Studies show that sunlight can be wipe out chlorine by 75-90% in a matter of two hours.
You should keep your outdoor pool or spa's Cyanuric Acid level at 0-30 parts per million (PPM).
When the pH levels are imbalanced, it renders the free chlorine ineffective and the levels decrease. Too little free chlorine forms chloramine and it is this combined chlorine that results in your pool's cloudy appearance.
Chlorine issues often cause cloudy water. Adding a recommended dose of pool shock to your pool can clear it right up. Poor circulation or filtration can contribute to cloudy water. Make sure your pump and filter are working properly.
The main reason for high CYA levels in your pool is from using too much stabilized chlorine. When the pool water evaporates, CYA remains in the water, much like other chemicals such as salt and calcium. As an example, 1 lb. of trichlor in a 10,000 gallon pool will raise the CYA level by 6 ppm.
Run your filtration system for eight hours every day over summer. Back-wash it if you have a sand filter and clean cartridges with Filtrite Filter Cleaner and Degreaser. Add 50 grams of Sanit-eezy Performance per 10,000 litres of pool water. No-one should swim for at least 30 minutes after this.
Skim the top of the pool for debris that may have settled on the pool surface. Add one pound of diluted granular shock to the water for every 7,000 gallons of pool water. Run the filter for 24 hours and retest the water. The slimy looking film can be an early onset of algae.
Along with balancing the pH levels of your pool water, muriatic acid is strong enough to kill mold, remove rust stains, get rid of calcium deposits, and clean the surfaces of your pool.
Baking Soda
Most remedies call for adding additional chlorine into the water. If your water's pH balance is between 7.2 and 7.5, however, you can add baking soda to the water to help clear it up. This serves as a replacement for chlorine because baking soda is a natural cleaning agent.
Saltwater pool manufacturers recommend maintaining cyanuric acid levels around 60-80 ppm. This is a bit higher than the 30-50 ppm range recommended for non-saltwater pools. And if you live in an area where your pool gets a lot of direct sunlight, you may even consider bumping your cyanuric acid up to 80-100 ppm.
CYA is a pretty strong acid on its own, so the best way to add it is to dissolve it in a bucket of warm water. Then go all around and pour the solution just inside the edges of the pool. For safety's sake, wear gloves and goggles when you mix it.
You should only add stabilizer if your levels are below 30ppm. Usually, all you have to do is check the level of stabilizer (cyanuric acid) in your pool every week to judge whether it's doing the job or not.
We also found that cyanuric acid is denser than water so it sinks to the bottom of a body of water.
All alkaline materials are buffers. Cyanuric acid happens to be the most common buffer found in pool water. In effect, cyanuric acid helps stabilize both chlorine and pH. It binds with chlorine to prevent photolysis and it keeps pH elevated.