You might have an infestation of algae, fungus or bacteria that can deplete normal chlorine levels and it is possible for this to occur without many visible signs. Your pool may appear to have a dusty look on the pool bottom. If you brush it and it clouds the water, then it is most likely a Mustard Algae.
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.
Maintain Proper pH Levels
Your pH levels affect your chlorine levels and the ability for the chlorine to do its work properly. 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.
Raise the Level of Pool Chlorine
Raising pool chlorine can be much easier than trying to lower chlorine levels. Simply adding chlorine in the form of chlorine tablets, granular chlorine, liquid shock or powder shock will increase the total amount of chlorine within the pool.
Things that cause low free chlorine levels are excessive sunlight, high bather loads, and improper water chemistry. Not having enough chlorine in your swimming pool will also cause the little bit of chlorine that's in there to be used up faster too.
If your total chlorine level is high, you will use a non-chlorine shock; if it is low, you will use a chlorinated shock. As a rule, you will need to raise free chlorine to 10 times your combined chlorine to hit what is known as “break point.” Therefore, it is good to deal with combined chlorine while it is still small.
When you're shocking a pool, the goal is to raise the free chlorine level of the pool water to roughly 10 times the combined chlorine level.
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.
Instead of adding chlorine to sanitize a saltwater pool, you add salt, and then a chlorine generator converts it to chlorine. When the free chlorine level is low, that usually means it's time to add more salt, but it may mean a couple of other things as well.
Diluting your pool water by draining and adding fresh water is a great option if you only need to lower your chlorine levels by 1-2 ppm. Remember that you're draining the other chemicals in your pool too, so make sure to do a pool water test when you're done.
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.
Daily as needed and indicated by measurement. One caveat, however: if your total alkalinity and pH are not where they should be, you will find it difficult to keep enough free chlorine in your pool water. Adjust your alkalinity first, then correct your chlorine.
So, not only is shocking a saltwater pool okay, but it's actually important to your pool's health. Shocking is the process in which you overload your pool with chlorine (3-5 times the normal amount) to improve your pool's cleanliness and kill off organic matter.
Your salt levels will vary depending on the type of chlorinator you have. If you're using the Water TechniX Salt water chlorinator then you should try to aim for a salt level of around 3,000 to 4,000 ppm.
Chlorine pools are more traditional and are also cheaper than most saltwater pools. However, they can be more difficult to maintain over time. Because there is no generator making chlorine, you will need to add chlorine into the pool on your own.
Strong Smell of Chlorine
A healthy, safe pool will have little to no odor. That smell comes when your pool is out of balance. The smell of chlorine arises when the chemicals are dealing with a lot organic material like sweat, urine, and bacteria in your pool.
How Often Should I Shock My Pool? Shocking your pool regularly will help to keep the water clean and free of contaminants. You should aim to shock your pool about once a week, with the additional shock after heavy use. Some tell-tale signs that your pool needs to be shocked are cloudy, foamy, green, or odourous water.
Shock Your Pool
Another method of breaking chlorine lock is shocking your pool. Bring your chlorine levels to 20ppm or three times higher than the current levels. We recommend using a non-chlorine oxidizing shock until your free and total chlorine reads the same.
You cannot overshock a swimming pool or add too much. Adding too much shock or overshocking your pool will kill off algae. The negative of adding too much shock is it will upset the chemical balance of your pool.
After Shocking Your Pool
It is safe to swim once your chlorine levels are around 5 ppm or after 24 hours.
Liquid chlorine and granular shock have the same active chemical that sanitizes your pool, what changes is the strength and the way you use it. Liquid chlorine is less costly, unstabilized and comes in liquid form. Granular shock is stabilized and comes in a solid form that dissolves in your pool.
Using liquid chlorine raises the pH of the water.
Liquid chlorine does not raise pH. When added to water, liquid chlorine (which has a pH of 13) makes HOCl (hypochlorous acid – the killing form of chlorine) and NaOH (sodium hydroxide), which raises pH.
A chlorine level of between 3-5mg/l must be maintained in your hot tub at all times. The addition of chlorine will depend upon usage and bathing habits. It could be daily or every 2-3 days (for 1mg/l add 2g per 1000 litres).