FAQ

How to Add Chlorine Tablets to Your Pool

Whether you’re new to pool ownership or you’re a seasoned pro, we know that keeping your pool free of bacteria and debris is a top priority. But testing your pool water and adjusting your chlorine levels can be a time-consuming task – and that’s after you’ve already spent hours skimming leaves and scrubbing the pool walls!

But the good news is that you can make pool sanitation easy with chlorine tablets. They’re premeasured, fuss-free and affordable, and just like liquid chlorine, they keep your pool sanitised all year round. 

But like most people, you’re probably wondering how chlorine tablets work. Do you put them in a floating dispenser or straight in the pool? Can they go in the skimmer? And how long do they last before you need to replace them? In this guide, we’ll give you the lowdown on what chlorine tablets are, how they compare to liquid chlorine, and show you two convenient ways to add them to your pool. To finish, we’ll answer some frequently asked questions, like how often you should replace the tablets, whether you can use them to shock your pool and what to do if they’re not dissolving fast enough. Let’s get stuck in!

Why choose chlorine tablets?

Unlike liquid chlorine, chlorine tablets are blocks made of compressed calcium hypochlorite, a household bleach, and cyanuric acid (CYA), a stabilising agent. The tablets dissolve in water to produce hypochlorous acid, which sanitises your pool, while the CYA provides UV protection to minimise depletion. Chlorine tablets are a mess-free, low-maintenance alternative to liquid chlorine. Here’s why chlorine tablets are becoming a popular option for backyard pools:

1. Easy to use: 

Chlorine tablets are lightweight and easy to add to your pool. Unlike liquid chlorine, you don’t need to calculate how much you need or keep topping it up throughout the week. You just add one or two tablets , depending on the size of your pool, and wait for them to work their magic. In general, you’ll need one tablet for every 20,000 litres of water.

2. Slow release: 

The tablets release chlorine at a steadier rate than liquid or granular chlorine, so there’s no risk of over-chlorinating, spilling it or not using enough. This is handy if you’re going away or you don’t have time to chlorinate your pool.

3. Long-lasting: 

Compared to liquid chlorine, tablets have a longer shelf-life. They can last up to five years if stored in a cool, dry place. Liquid chlorine, on the other hand, will only last a few weeks before it becomes ineffective. As a result, you’ll need to buy it frequently – and you won’t be able to stock up when it’s on sale!

4. Higher concentration of chlorine:

Chlorine tablets pack a punch with a high concentration of chlorine. In fact, tablets can have up to 90 per cent chlorine compared to their liquid counterpart, which only contains about 12 per cent. Some tablets, like the Multi-Action Chlorine Tablets, also include algaecide to prevent and treat algae.

5. Affordable: 

While chlorine tablets seem more expensive than liquid or granular chlorine, they contain more chlorine and last longer. They also have a longer shelf-life and can’t be spilled, so you save money over the long run. 

6. Stabilised: 

Most chlorine tablets include a stabiliser or cyanuric acid (CYA), which reduces evaporation of chlorine and prolongs sanitation. Liquid chlorine doesn’t usually include a stabiliser, which means it gets used up quickly. To compensate, you’ll need to add stabiliser separately, adding yet another step to your pool sanitation routine. 

Note:

Check your CYA levels before adding chlorine tablets to your pool. If the levels are high, you may need to bring them down by diluting the pool water by dr

How to add chlorine tablets to your pool

There are two ways of adding chlorine tablets to your pool. Each has its pros and cons, so choose a method that’s right for your pool, budget and lifestyle. Let’s run through them.

Method #1: Floating dispenser

Another way of adding chlorine tablets to your pool is with a Small Floating Tablet Dispenser. This can fit 3 x 200 g tablets and provide controlled release of chlorine over five days. Alternatively, you could get a Smart Pod Tablet Dispenser that has the same features plus the ability to flip on its side when it’s empty, letting you know when you need to replace your tablet.

Another option is the Multi-Action Chlorine Floater, which is a floater and tablet combo. Unlike traditional dispensers, you don’t have to add tablets to the unit. The floater is just dropped into the pool and it can sanitise your water for up to a month, depending on the size of your pool and how often it’s used. It then floats on its side when it needs replacing.  

Floating dispensers are cheap and easy to install. You just put the tablets inside and deposit it on the water. The dispenser then relies on the circulation of water to move around your pool. The water then flows through the dispenser and dissolves the tablet. Adjustable vents also allow you to control the amount of chlorine that’s being released. 

The only problem with floating dispensers is that they can get caught in the skimmer, behind ladders, steps or pool toys. Shift it with a telescopic pole if it gets stuck or consider tying it down with some strings. Also, remove it from the pool before anyone goes swimming. Children could mistake it for a toy and accidentally touch the chlorine tablets, which can cause irritation or injury.

Pros
  • Affordable
  • Easy to use
  • Adjustable vents control the release of chlorine
Cons
  • Can be slow to dispense chlorine
  • Can get caught in skimmer, behind ladders or pool toys

Method #2: Automatic chlorine feeder

This option is the most expensive of the two, but it’s a safe and reliable way to add chlorine tablets to your pool. The tablets are simply loaded in the automatic chlorinator and you control the speed at which the tablets dissolve and the amount of chlorine that’s released. 

Automatic chlorinators work with your filtration system and need to be installed by a pool technician. They can be in-line, which means that they are installed into the water return line of the pool, or off-line, which means they are retrofitted on a separate line. 

Maintenance is minimal with automatic chlorinators. All you have to do is add the tablets, set your dial to 1–3 ppm and let the unit do all the work. And because it provides an even distribution of chlorine, you won’t get high concentrations of chlorine in any particular area. Just set and forget!

Pros

  • Easy to use
  • Low maintenance
  • Holds multiple tablets
  • Even and accurate distribution of chlorine

Cons

  • Can be expensive to set up

FAQs

Question 1: How many tablets do I need for my pool?

If you’ve got standard chlorine tablets (200g each), you’ll need one tablet per 20,000 litres. So for a pool that contains 60,000 litres of water, you’ll need 3 tablets every week to keep it sanitised. To be on the safe side, we recommend testing your water balance regularly and adding tablets as necessary.

Question 2: Can I put chlorine tablets directly in the pool?

We don’t advise putting chlorine tablets directly in your pool. They’ll sink to the bottom and the concentrated levels of chlorine will damage pool surfaces or equipment. What’s more, loose tablets are unsafe for swimmers. They may accidentally step on them and experience burning or discomfort. For best results, use one of the methods we’ve outlined above. 

Question 3: How long after adding chlorine tablets can I swim in the pool?

Because tablets dissolve very slowly, just make sure the filtration system has been running for a while (i.e. you’ve had at least one full cycle) and that chlorine levels are within range before you dive in. If you’ve got a floating dispenser, remove it before swimming. The chlorine levels around it could be higher and irritate swimmers. Also, it could be used as a toy by children or dogs.

Question 4: How long does it take for a chlorine tablet to dissolve?

It all depends on the size of your chlorine tablets. Standard tablets (200g) can take about 5 to 7 days to fully dissolve. Some factors that affect the rate of dissolution are the method of application (floating dispensers are slower), how often you run your pool pump (more circulation helps dissolve it) and chlorinator settings. 

Question 5: Why are my chlorine tablets not dissolving?

Depending on your application method, there are a few reasons why your chlorine tablet might not be dissolving. First, if your filtration system is off, you may not be getting enough water flow to break down your tablets. Make sure it runs for at least 8 hours a day for best results. If you have an automatic chlorinator, you may have the wrong setting on your output dial, or your control valve may be clogged, preventing water from flowing into the chlorinator. If that’s the case, contact a pool technician for advice and service. 

Question 6: Can I break down the tablets to make them dissolve faster?

It’s best to keep the tablets intact as they’re designed to release the chlorine slowly. If you break them up, the high concentrations of chlorine may be dangerous for swimmers. 

Question 7: Can you use chlorine tablets to shock a pool?

Chlorine tablets aren’t designed to shock a pool. The chlorine levels are too low and they’re released too slowly. Pool shock needs to be concentrated and fast, or algae and bacteria will multiply quickly and make your pool cloudy. Instead of chlorine tablets, use Liquid Chlorine or Ultra Shock.  

Takeaways

For pool owners who find liquid chlorine difficult or unpleasant to handle, chlorine tablets are a safe, affordable and mess-free way to keep your pool sanitised. By using one of our application methods – and  checking your water balance regularly – you’ll be able to save time, effort and money over the long run. Here’s what you need to remember:

  • If you’re using a floating dispenser, keep it away from ladders or pool toys and refill it every week (unless you’ve got a Multi-Action Chlorine Floater, in which case replace it every 2-3 weeks). 
  • If you have an automatic chlorinator, your job is easy! Just put multiple tablets inside the compartment and let the unit do all the work! 

Ready to sanitise your pool with minimal effort and maximum results? Then head to your nearest retailer to select from our range of chlorine tablets and dispensers. If you want to know more about pool care, check out our Pool Tips.