How to Use Chlorine Tablets in a Hot Tub
Chlorine tablets are a popular way to sanitise your hot tub and keep it clean from bacteria. Over the past few years this choice of sanitiser has become increasingly popular as some inflatable hot tub manufacturers such as Lay-Z-Spa have opted to recommend this to customers so as inflatable hot tubs have become popular, chlorine tablets have increased in popularity too. On the flip side many acrylic hot tub manufacturers do not recommend chlorine tablets for reasons that we will outline below. Please ensure that you follow your manufacturers recommendations to prevent damage to your hot tub. In this guide we will outline the good and bad things about tablets, how to use them and answer some common FAQs.
Why Are Chlorine Tablets Good?
- The slow-dissolving nature of the tablet means consistent dosing over time, which reduces the risk of chlorine dropping below the recommended 3-5ppm on your chlorine test strips.
- Chlorine tablets are very cost effective and arguably the cheapest way to kill bacteria in a hot tub.
- Tablets offer a good solution for those who don't use a hot tub for period as they ensure chlorine is dispensed slowly over time. Caution - see below point on how this can be misused.
Why Are Chlorine Tablets Not So Good?
- Chlorine tablets (Trichlor) are acidic which means PH and Alkalinity will reduce when using this product. This means more PH balancing is required than using a more PH neutral product like chlorine granules.
- It is common for chlorine tablets to create a high chlorine level which can be damaging to hot tub components. This does tend to be user error as some hot tubbers see tablets as a 'set and forget' system, which leads to misuse of the product. As with any hot tub sanitiser, PH and alkalinity levels must be balanced.
How to Use Chlorine Tablets in a Hot Tub
Where to Put Chlorine Tablets in a Hot Tub?
Chlorine tablets are slow dissolving and therefore need to be placed in either a floating dispenser, in-line chlorine feeder or a skimmer basket. This ensures good flow to allow the tablets to dissolve and also ensures that the tablets are never in direct contact with the hot tub surface and out of reach for hot tub users.
How Many Chlorine Tablets?
For smaller hot tubs we recommend 1-3 tablets and for larger hot tubs 3-5 tablets. Unfortunately this question doesn't have one simple answer and it depends on lots of factors like water flow, usage and hot tub size. Test your water regulary after start-up and see how the levels are sitting. If the tablets are not coping with the demand then add more or if the chlorine level is too high then reduce the amount. You may also need to boost levels every now and then with either chlorine granules or chlorine shock pot, this is due to the slow dissolving nature of chlorine tablets, which means they react slower than granular chlorine.
What Size Chlorine Tablets for a Hot Tub?
There are two main sizes of chlorine tablet on the market. A 200g large chlorine tablet (3 inch diamater) and a 20g small chlorine tablet (1 inch diameter). The large 200g tablets are mainly designed for swimming pools whilst the 20g tablets are for hot tubs and small splasher pools. Due to the water capacity, we do not reccomend using large 200g swimming pool tablets in a hot tub as they will lead to high levels of chlorine which could cause damage to components. Use 20g chlorine tablets only in hot tubs.
How Long do Chlorine Tablets Last in a Hot Tub?
Small 20g chlorine tablets will dissolve slowly over a period of 3-7 days depending on water flow, water temperature and hot tub usage. Monitor your first batch to ensure you know the dissolving time in your hot tub for future reference.
