While both granular and liquid chlorine has their pros and cons, granular chlorine is more common in home pools. It's cheaper, easy to use, easy to store, and lasts a long time. More premium pools often go for liquid chlorine because of its long-lasting effect on the pool. However, there's no watertight categorisation.
Both liquid and powder shocks contain the same active chemical used for pool sanitation, but their usage and strength are different. Other than coming in a different form, liquid chlorine is also more budget-friendly and unstabilized. On the other hand, powder shock is easy to stabilize, and its solid form dissolves.
pH Impact: One consideration with liquid chlorine is its effect on pH levels. Since liquid chlorine has a high pH of around 13, it's easy to throw off your pool's chemistry with this chemical. Regular monitoring and adjustment of pH levels are necessary when using liquid chlorine.
Liquid Chlorine or Bleach is the tried and true standard chemical of choice for most pool service professionals. It is easy to use and relatively inexpensive and it has the least side effects of any of the chlorines you can choose from.
Granular chlorine when kept in airtight containers that are cool and dry can last for over five years, though when stored otherwise and exposed to humidity it can dissolve in under two years.
Chlorine and shock are not the same thing. Shock has a more intense chemical strength than the traditional chlorine sanitizers, and it also differs in how you should apply it to your swimming pool.
If you're adding your regular doses of chlorine (i.e. not shock), a good rule of thumb is to wait 4-8 hours or until the water has experienced 'turnover' and has been cycled through the whole system. If you're shocking your pool, you'll have to wait longer.
Calcium hypochlorite is likely the most effective pool shock available because of how strong the chemical is compared to the two other options. Sodium di-chlor stays in the water longer than any other substance and includes a stabilizer that raises the levels of cyanuric acid in the pool, which reduces chlorine loss.
Hypochlorous acid is the most effective form of free chlorine residual for disinfection. Depending on pH, hypochlorous acid may break down further into a hydrogen ion and a hypochlorite ion. Hypochlorite ions are much less efficient disinfectants.
The key selling point of granules over tablets is their speed. Because they dissolve quicker, they can get to work against algae and bacteria faster. It's this quality that makes them popular as pool shock treatments.
The effect of excess chlorine in pools is an alteration in pH levels of pool water, making it more acidic. Signs of high chlorine levels can include itchy sensations in the eyes, nose and throat, nausea, vomiting, dizziness, lung irritation, and skin rashes.
By carefully adding muriatic acid, you can reduce high pH levels, preventing water cloudiness, ineffective chlorine, and scale formation. Additionally, muriatic acid's corrosive properties enable it to remove stains, scale, and calcium deposits from pool surfaces and equipment.
In household cleaning products
Chlorine bleach is one of the most commonly used disinfectants. It contains sodium hypochlorite dissolved in water. Chlorine is good at removing stains from fabrics, disinfecting surfaces, and removing mold and mildew.
Biofilm or organic material in the water, such as sunscreen, leaves, or algae. Pool covers trapping chlorine and causing it to dissipate more rapidly. In some cases, your chlorine levels might be too high, and this can cause your test kit reagents to bleach out, making it look like there's no chlorine in your pool.
There are several advantages of chlorine in liquid form compared to granular/powder form. First, liquid chlorine disperses in your pool easily and effortlessly. On top of that, it doesn't leave behind any residue. Liquid chlorine has no effect on Cyanuric Acid or Calcium Hardness, which is a good thing.
Ozone: preferred by many public pools
It is twice as effective as chlorine. Ozone makes water pleasant, odorless and good-tasting (it is also used to disinfect drinking water). This is why it is very popular with public pools which can amortize its high cost of acquisition more easily.
Trichlor is the most popular choice of chlorine for regular use in home pools. It does, however, have a higher (and potentially more effective) chlorine saturation and can alter the pH of the pool slightly. However, dichlor has a neutral pH level. This means it won't affect the natural pH of the pool.
In addition to causing irritation, high levels of chlorine can also cause premature wear and tear to the filter and other mechanical parts of the pool. Fortunately, chlorine is light sensitive. So a few days of good sunlight should help burn off the excess chlorine and help get it back to normal levels.
A simple rule of thumb to follow when you shock your pool is to dissolve one pound of either calcium hypochlorite or sodium dichlor for every 10,000 gallons of pool water. If you are using sodium hypochlorite, i.e., liquid chlorine, the ratio comes out to 10 ounces for every 10,000 gallons of pool water.
Dissolve the shock in water (if you're using granular chlorine). Add the shock to the pool. Let the shock circulate for at least 8 hours (or 15 minutes if you're using non-chlorine shock). Test and rebalance your water.
Unopened containers of chlorine granules or tablets, for example, can remain effective for about two to three years if stored in a cool, dry, and well-ventilated area. It's important to note that chlorine can degrade over time when exposed to heat, moisture, or sunlight.
You should add chlorine within 48 hours of filling your pool with water. In just 24 hours, bacteria and algae will begin to grow and contaminate your water. After that point, you'll need to shock the water with high levels of chlorine, and you'll likely need to do additional vacuuming to get the pool clean.
Exposure to high levels of chlorine can cause lung irritation, skin and eye damage, and provoke asthma. Not only is it bad for your health, but it can be bad for your pool due to the increase in chlorine. High chlorine levels decrease the pH of your pool's water, making it more acidic.