Liquid Chlorine for swimming pools

Pools that are sanitized using only liquid chlorine are not very common in Australia because most pools use salt. However, some people are rethinking salt for a range of reasons. Remember, salt is what the pool industry is familiar with so for this reason, salt water pools (which don’t use liquid chlorine) are far more popular…for now.

Most popular chlorination systems in Australia

Liquid Chlorine

Strengths and weaknesses
Liquid chlorine is underrated
  • No electronic equipment needed
  • Cheap to buy
  • Fast acting in water
  • Heavy to transport
  • Will bleach clothes

Chlorine Tablets

Strengths and weaknesses
Chlorine Tablets can make life easy
  • Have built in UV protection
  • Helps keep pH in balance
  • Easy to transport and handle
  • Frequent use blocks chlorine strength
  • Dispenser floating around is annoying

Salt Water Pool

Strengths and weaknesses
Salt is common and easy to run
  • Salt is cheap and lasts a long time
  • Lower maintenance than the others
  • Process is well understood
  • Salt bags are heavy to move
  • contaminated salt causes staining

Benefits of Liquid Chlorine

No salty water

One of the main benefits of liquid chlorine is that your pool water does not have around 200kgs of salt in the water. Because of this, some swimmers believe that this makes the water feel nicer to swim in. Also, chlorine pools do not need any salt content in the water to keep it safe and chlorinated.  This absence of salt also is kinder to your pool surface and fittings.

Cost-effective

Some claim that salt pools are much cheaper to run than a liquid chlorine pool. However, if the right amount of cyanuric acid (CYA) is maintained in the pool then liquid chlorine can still be quite economical. This is because the CYA will protect the chlorine from UV light from the sun.  This means that the amount of chlorine required is greatly reduced. Also, did you know that 65% of pools in the USA use liquid chlorine and not salt?

Cyanuric acid will preserve chlorine

Often those who complain about the amount of chlorine their pool is consuming often have low or no CYA in the water. This means that the UV sunlight is zapping all their chlorine so more is needed to maintain the right level. When the right levels of CYA are maintained, then the chlorine usage falls dramatically. We have a page about this issue that you can find here. Remember, don’t let the CYA  level get too high or it can result in unsafe water.

Pool maintenance can be easy

Also, if you use a chlorine feeder (doser) many newer models will now also feed hydrochloric acid as well. This means that the pH levels and the chlorine levels are both maintained automatically by the equipment. This is not only very convenient but also goes a long way to keeping the water safe to swim in. However, you need to make sure you have liquid chlorine and acid in the feeder drums otherwise the machine will not work!

Salt staining is a thing of the past

Another benefit is that you are not constantly adding salt to your pool. This means that you will not fall victim to a stain from contaminated salt. Salt staining is a real issue for some pool owners, particularly if cheap or contaminated salt is used. Most salt pools consume around 300 kg of salt every year. That’s a lot of salt!  Each bag increases the odds that you will strike a contaminated bag and stain your pool.

Salt in swimming pool
Swimming pool surface stained from contaminated salt.

“These days, pool salt comes from all parts of the world which means the quality varies more than it has in the past.  Because salt staining and discoloration are becoming more common, it is smart to spend a few extra bucks on good quality salt.  It will work out cheaper in the end”

"Did you know that liquid chlorine is more than 6 times stronger than household bleach? Keep this in mind when handling chlorine as those jeans will be ruined if there is a small spill or splash"

“Liquid chlorine is cheaper to buy than powdered chlorine.  It is also easier to control the chlorine level in larger pools as a lot can be added quickly.  The ability to regulate chlorine levels is one reason why liquid chlorine systems are so common in commercial pools.”

Liquid chlorine drum

Downsides of liquid chlorine

Liquid chlorine drums are heavy

The biggest downside to liquid chlorine is transporting the heavy drums from the store to your pool. This process can be very difficult for some pool owners as the drums range from 16 – 26 kgs. Furthermore, if any chlorine drips or spills in your car, it will permanently bleach the carpet. Remember, this product is 4-6 times stronger than household bleach!  Investing in a small trolley to move the drums around is a great idea.

Liquid chlorine in summer

In the summer months, the quantity needed to keep the water safe will increase significantly. This will result in frequent trips to the pool shop for more chlorine. Swimming also reduces chlorine so be prepared for when those pool parties are happening as the chlorine use will spike during these times.  On the other hand, in the winter time the chlorine usage is much lower. At this time of year, a single drum can last nearly 3-4 months.

Automatic chlorine feeders

Another consideration is that you will likely need a device to feed and measure the chlorine levels in your pool. This equipment needs to be maintained and serviced regularly. A quality chlorine feeder system can be as high as $2,500 to install. Also, you will also need to replace the probes (that test the chlorine level) every few years. They are usually around $200-$300 to replace. These also need to be checked and calibrated each year by a service technician to ensure they are testing properly.  It is important to do these steps because if the probes become fouled or malfunction then you water can ‘test’ as safe but actually have no chlorine at all.

Adding chlorine manually

On the other hand, liquid chlorine can be added manually which means that you don’t need an automatic chlorine feeder. However, this can be very annoying and tedious as chlorine needs to be added several times a week in summer. You will also need to manually test the water to make sure the pH and chlorine levels are right. Frequent handling of heavy drums can also result in spills and bleached clothing.  

Liquid chlorine feeder
Fully automated liquid chlorine feeders measure and dose chlorine as required.

“Liquid chlorine feeders automatically dose chlorine into your pool.  They use electronic probes that test the chlorine level in the water and then dose the amount required to properly chlorinate the pool”

Final thoughts

Nothing, no matter what they say, is zero maintenance.  Unless you are testing and dosing manually, you will rely on some form of electronic equipment to maintain the water.  None of these systems are maintenance-free. It is important to have them checked and maintained by your pool professional.  If you do this, it will be fine.  We meet a lot of pool owners who have faced expensive issues with their pool because a testing probe failed a long time ago and they have done nothing about it.