Weekly Chlorine Tablets
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!
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:
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 draining some of your pool water and topping it up with a hose. While CYA makes your chlorine effective for longer, too much can have the opposite effect.
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.
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.
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!
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.
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.
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.
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.
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.
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.
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.
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:
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.