Hot Tub Chemicals Guide

It is absolutely essential to sanitise the water and remove and prevent bacteria growth. For this you will need Chlorine.

Balanced water chemistry takes into account the alkalinity and pH of your water, so you may require a pH reducer, pH increaser and an Alkalinity increaser.

Other hot tub chemicals are classed as non-essential but may be required in certain circumstances.

For beginners, we suggest getting the ClearWater® Hot Tub Starter Kit. This includes the basics to get started and it might be all you need.

The short answer is no.

Depending on the frequency of use, some chemical levels may change more than others but it is generally a case of periodically making some minor adjustments, such as adding some chlorine.

We recommend testing the water a few hours before you want to use your Lay-Z-Spa and making necessary adjustments, if any are needed.

Keep scrolling down this page and you will find recommended dosage and advice for the essential hot tub chemicals.

All ClearWater® hot tub chemicals include dosage recommendations on the packaging.

The correct order to manage and balance hot tub chemicals is:

1. Total Alkalinity (80‑120 ppm)
2. pH levels (7.2‑7.6)
3. Chlorine (3‑5ppm)

Shock dosing a hot tub is adding a larger quantity of sanitiser, such as Chlorine, to break down organic matter, get rid of bacteria and any contaminants in the water making it safe to use. A shock dose can also help with any loss of water clarity or quality.

Your Lay‑Z‑Spa hot tub water should be shocked:

• When you first fill up your Lay-Z-Spa
• After periods of heavy usage
• After a long period without use
• After a loss of water clarity or quality
• After refilling with fresh water

You need Chlorine Granules to shock dose a hot tub. Chlorine tablets are slow releasing and only used to maintain the correct daily chlorine level.

1. Check the water capacity of your hot tub and measure the Chlorine Granules accordingly. The size of your hot tub will impact how much chlorine you need to add. Use the Chlorine Dosage Guide to see how much chlorine you need to add to your Lay‑Z‑Spa.
   
2. Dissolve the right quantity of Chlorine Granules in a jug of warm water and pour into your hot tub. Activate the AirJets for a few minutes to circulate the chemicals evenly throughout the water.
   
3. After shock dosing your hot tub, you will need to wait a minimum of 24 hours. Then, test the chlorine level with the dip test strips and make sure levels are 3‑5ppm. Add more Chlorine if necessary and balance the pH and Total Alkalinity before using the hot tub. 
   

Total Alkalinity (TA) is the measure of your hot tub water’s ability to neutralise acids. It acts as a buffer to neutralise pH.

But what does this all mean? It may sound a bit complex so it's just easier to remember: If the alkalinity is imbalanced, it can be hard to balance pH levels and even chlorine. So, the advice is to balance your TA before doing anything else.

Balanced Total Alkalinity helps control the pH levels. Together these help maintain stable chlorine levels.

If either Total Alkalinity or pH levels are off, you may notice a drop in water quality, cloudy water, itchy skin and it could be affecting your Lay-Z-Spa heater pump, pipes and even the liner.

The correct level to aim for is between 80 and 120ppm (parts per million).

• For low TA levels below 80ppm you will need to use Total Alkalinity Increaser. The amount of TA + you need to add to your hot tub depends on the volume of water and how low your readings are. As a guide ‑ a hot tub of 1,000 litres requires 18g to raise Total Alkalinity levels by 10ppm (parts per million).
  
• For high TA levels above 120ppm you will need to use PH Minus. The amount of pH decreaser you need to add to your hot tub depends on levels are and on the volume of water. Check the dosage rates on the back of the bottle and measure accordingly.

Low Total Alkalinity:

• Irregular, low pH levels
• Corrosive
• Itchy skin & burning eyes
• Loss of water quality

High Total Alkalinity

• pH levels will be high
• Chlorine levels fluctuating
• Cloudy, milky foamy water
• Scale build-up

High TA can be cassed by:

• Cosmetics, body lotions, make up etc
• Hard water with a high pH
• Water has been in too long and TDS* is high

Low TA can be caused by:

• Rainwater
• Sweat
• Organic contaminants brought into the water by users.

pH measures how acidic or alkaline your water is and the ideal range for hot tubs is between 7.2 and 7.6.

Balanced pH is necessary for other chemicals to work properly and imbalanced pH levels can impact your hot tub components and cause skin irritation.

When testing the water, aim for s reading of 7.2 and 7.6

• For low pH levels below 7.2 you will need to use pH Plus to help raise the pH levels and balance the water.
  
• For high pH levels above 7.6, use pH Minus to help bring those levels back down into the recommended range

The amount of pH increaser or decreaser you need to add to your Lay-Z-Spa depends on the volume of water and how low your readings are. Refer to the dosage information will be printed on the individual chemical bottles.

Low pH:

• Less effective chlorine
• Corrosive
• Dry skin & burning eyes
• Loss of water quality

High pH

• Skin & eye irritation
• Chlorine levels fluctuating
• Cloudy, milky foamy water
• Scale build-up

Chlorine is a sanitiser that controls and prevents bacteria growth and is essential for the hot tub water to be clean and safe to use.

The recommended Free Chlorine* level in a hot tub is 3‑5ppm (parts per million).

Click on the Chlorine dosage guide for recommended amounts.

*Free Chlorine refers to the amount of chlorine in your hot tub that is available to sanitise or disinfect the water, keeping it safe for users.

Topping up the chlorine could be on a daily or weekly basis, very much depending on how much you use your Lay-Z-Spa.

Some Lay-Z-Spa owners add a measure of chlorine immediately after using the hot tub, others test the water a few hours before they want to use it.

Low chlorine results below 3ppm risk a build-up of bacteria and a quick loss of water quality.

You will need to add the appropriate amount of chlorine to restore the balance.

Your options are:

• Chlorine granules - the most accurate way of raising chlorine levels in a short space of time, including a shock dose
• Chlorine tablets - these are slow release so could take some time to raise Free Chlorine ppm if it is very low.
• Fast Action Tablets - These go straight into the water and a great for a quick boost of chlorine.

For high chlorine levels above 5ppm, we strongly recommend not using your Lay-Z-Spa.

We would suggest you drain some of the water from your Lay-Z-Spa and re‑fill with fresh water. This will help to dilute the excess chemical.

Low chlorine levels:

• Loss of water quality
• Cloudy water
• Bacteria growth
• Bad smell
• Bio film

High chlorine levels:

• Itchy skin & burning eyes
• Corrosive
• Discolouration