Look for algae. Algae growth in your pool will rapidly consume free chlorine. High temperatures, high levels of phosphates, dirty or clogged filters and low chlorine levels can promote algae growth. Scrubbing with a brush can remove algae from surfaces if they have accumulated in one place.
One of the causes of a high chlorine demand is an excessive buildup of algae and phosphates. Although you're adding chlorine to your water, bacteria or algae are overpowering the chemicals causing it not to show up on tests strips or in water kits.
If your water's pH is too high, it hinders the chlorine's ability to efficiently clean the pool. A water pH level that is too low causes the chlorine to dissipate more quickly. Therefore you'll need to add more chlorine to accomplish the task.
Remove Chlorine Through Chemical Neutralization
Likely the best chemical to use for chemical neutralization is potassium metabisulfite, which comes in the form of small tablets. Once the tablet dissolves in the water, it will effectively neutralize the chlorine before evaporating.
Yes, boiling water for 15 minutes is one way to release all the chlorine from tap water. At room temperature, chlorine gas weighs less than air and will naturally evaporate off without boiling. Heating up water to a boil will speed up the chlorine removal process.
There are several types of filters that remove chlorine and chloramine including Reverse Osmosis, Ultraviolet light and Activated Carbon. One of the most efficient technique for chlorine and chloramine removal is Activated Carbon.
Look for algae. Algae growth in your pool will rapidly consume free chlorine. High temperatures, high levels of phosphates, dirty or clogged filters and low chlorine levels can promote algae growth. Scrubbing with a brush can remove algae from surfaces if they have accumulated in one place.
Algae create a chlorine demand in the water for itself, consuming chlorine that should be working on other contaminants. As it expels carbon dioxide, the pH level of pool water can rise. Algae are kind of like weeds in your garden.
If you test your pool water and can't get a chlorine level reading at all it may be due to a very high chlorine demand. A high chlorine demand is the inability to keep an adequate level of chlorine in the pool water even though the water appears to be balanced and properly maintained.
The Bottom Line about Pools and Chlorine
As mentioned above, you could probably swim in a pool without chlorine without any major health issues. However, long-term use of a pool lacking chlorinated H2O could make you sick or, at the very least, contribute to rashes and other types of skin irritation.
Direct sunlight (UV)
Direct sunlight breaks down chlorine. Without a stabilizer (cyanuric acid) in the water, as much as 90% of free available chlorine could be destroyed within just two or three hours.
Cyanuric Acid (CYA), also called stabilizer or conditioner, protects chlorine from sunlight.
The ultraviolet rays of the sun can reduce chlorine by up to 90 percent in two hours! And if it's a hot day, warmer water tends to breed more bacteria, and so the pool's chlorine gets used up faster and must be replenished more frequently.
Baking soda, also known as sodium bicarbonate is naturally alkaline, with a pH of 8. When you add baking soda to your pool water, you will raise both the pH and the alkalinity, improving stability and clarity. Many commercial pool products for raising alkalinity utilize baking soda as their main active ingredient.
Grab a brush and some baking soda. Bicarbonate, the active ingredient in baking soda, is an effective spot treatment to help kill the algae and loosen it from the wall. Make sure you really get every last particle free; black algae has particularly long and stubborn roots which makes it a persistent strand.
So if the pool water isn't cloudy and the 'dirt' is clinging to the walls after brushing, the problem is likely be yellow/mustard algae. Yellow/ Mustard algae is very resistant to even high chlorine levels and will grow and thrive in a chemically well-balanced pool.
People who have aquariums or simply don't want to be exposed to chlorine in drinking water often look for ways to remove it. It will kill fish and is a toxic chemical. Letting water sit does remove chlorine. Chlorine is a gas that will evaporate from standing water if the air is warm enough.
Carbon filters can effectively remove or reduce many contaminants from water including VOCs, chlorine, lead, fluoride, pesticides and much more.
Chlorine (Cl)
Activated Carbon filters are excellent at removing chlorine and related poor taste and odor. High quality activated carbon filters can remove 95% or more of the free chlorine.
What is this? However, to successfully convert the saltwater and generate chlorine, it needs the right temperature to work at. This temperature is above 60°F (or 16°C). So, if the pool temperature falls below this, the SWG will completely shut down.
Alternatively, UV may act to destroy chlorine, reducing the residual in water. Monochromatic UV light was more effective in degrading monochloramine whereas polychromatic UV light was more effective in degrading free chlorine.
Hot Weather
The result? You lose free chlorine. In the heat of the summer, consider adding twice as much chlorine to your pool so you maintain an adequate level.
The degradation rate of chlorine in direct sunlight without CYA is 75 % loss in 2 hours or a complete loss of chlorine in 4 hours. CYA will keep the chlorine in the water 8 times longer than without it.
Most of the CYA will dissolve in the first 24 hours, but the level can sometimes continue creeping up for several days to a week.