Chemicals Guide


Looking for Hot Tub Chemicals to buy?


Water Problem Solving Chart

Are you having problems with your hot tub water? If so check out the problem and symptoms in the table below.

Green / Cloudy Water / Slippery Sides Algae Shock dose with chlorine (see start up dose or our guide to chlorine)
Too much chlorine Overdose Allow time to naturally dissipate or buy a chlorine reducer
PH hard to control Alkalinity low Adjusting PH levels in your Lay-Z-Spa
Can't maintain chlorine levels Chlorine demand of water too high up start up, after holidays or due to excess contamination or neglect Shock dose with chlorine (see start up dose on product instructions). Repeat after 24 hours if necessary
Cloudy water Poor chemical control or inadequate filtration Clean or replace filter cartridge, check chemical levels using either ClearWater Dip Test Strips. Adjust if necessary (chlorine/PH). If problem persists buy a clarifier to remove small particles
Rough pool sides / edges Scale formation due to high calcium levels in water Ensure PH levels are correct using ClearWater Dip Test Strips and use a pool scale inhibitor to stop calcium precipitating out of water
No colour change on test strip dip test Too high chlorine leading to bleaching of indicator pads (over 15ppm chlorine) Check expiry date on ClearWater Dip Test Strips. Wait for chlorine level to drop and re-test
Foaming Detergent present from incorrect cleaning products or excessive algaecide use Reduce water level and top up with fresh water. Avoid domestic household cleaners.You can also use Clearwater Foam Remover if the problem persists.

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General Safety Tips

  • Do not leave non swimmers / children unattended
  • Do not overload the spa
  • Avoid sitting on spawalls
  • Do not allow diving
  • Do not use during thunder storms
  • Do not use electrical appliances near water
  • Use plastic rather than glass around the spa
  • Have a First Aid Kit available for any accidents

Chemical Handling

  • Read instructions thoroughly on each product/box before use
  • When pre dissolving chemicals always add chemicals to water and not vice versa
  • Never mix different chemicals in concentrated forms including these kit products but also with other products like bleach or weedkillers – a dangerous reaction may occur
  • Always pre-dissolve chemicals in a clean,plastic container in a well ventilated area
  • Avoid spillages but in event of spillage clean up using clean receptacles and dispose in the pool. Flush cleaned spill areas with water
  • Never use unlabelled chemicals
  • Wash hands after handling chemicals

Storing Chemicals

  • Store chemicals well away from children and pets
  • Store in a secure,cool and dry place

Starter or Shock Dosing

Use ClearWater Dip Tests to test the water supply for pH and Total Alkalinity levels. At this stage the water is unlikely to have much chlorine (if any) so to avoid algae and bacteria from the start add a "shock” or starter dose of ClearWater Stabilised Chlorine Granules. Read our chlorine guide for more information about shock dosing your spa.

Allow 50gms of chlorine granules to every 1000 gallons (4545 litres).

All Lay-Z-Spa pumps use a cartridge filter as standard. It is a combination of circulating water through the cartridge to collect suspended particles, together with good chemical water treatment, that helps you maintain clear, clean and healthy water.

Using ClearWater 3 Way Dip Tests you are able to quickly and accurately assess the condition of your water and make adjustments to chemical levels with the appropriate chemicals added where necessary. Test daily when the spa is in use and twice weekly when the hot tub is not is use.
Free Chlorine 1 - 3 ppm* *ppm = parts per million
pH 7.2 - 7.6  
Total Alkanlinity 125 - 150 ppm* *ppm = parts per million

When using ClearWater Dip Tests follow the instructions on the bottle for best results being observant of the optimal reading times and always holding strips level (to avoid indicator pad colours mixing).

By regular testing of your hot tub water you will soon learn how various activities like refilling, topping up, adding chemicals and general usage can affect various test readings.

Chemical Water Treatment

Bacteria Control – ClearWater Stabilised Chlorine Granules are used to disinfect the spa water and keep it free from bacteria, some of which may be hazardous to health. ClearWater Chlorine Granules are quick dissolving and relatively pH neutral.

Normal Dosing - ClearWater Stabilised Chlorine Granules:
1000 Gallons (4,545 Litres) 9 Grams
2500 Gallons (11,364 Litres) 23 Grams


To ensure the ideal reading of 1 – 3 ppm is maintained it is advised to aim for 3 ppm to provide a useful "buffer” for fluctuating conditions such as bathing loads and hot weather. The rate of chlorine consumption can and does vary depending on different conditions and chlorine will be consumed even when there is no swimming (i.e. by sunlight or by algae). Because of this,the only way to be sure that there is chlorine present in the water is to test regularly.

pH – The pH scale of 0 – 14 measures acidic or alkali conditions respectively.The middle reading of 7 is neutral, so spa water with a pH below 7 is acidic and pool water with a pH above 7 is alkaline.

For above ground pools the ideal pH level is slightly alkaline between 7.2 – 7.6, ensuring plant protection and bather comfort are maintained (the pH level of the eye is consistent with this level).
8.5. 8.0 Skin / eye irritation. Scale formation. Reduces chlorine effectiveness
7.2 - 7.6 IDEAL LEVEL
7.0. 6.5 Plant corrosion especially metals. Unpleasant smells and bather discomfort. Chlorine quickly used up


If the pH of your spa water is above 7.6 then use ClearWater pH Minus to reduce it,using the application instructions on the bottle.

If the pH of your spa water is below 7.2 then use ClearWater pH Plus to increase it,using the application instructions on the bottle.
Read our PH guide for more information about adjusting Lay-Z-Spa PH levels

Cleaning & Maintenance

Periodic cleaning of waterline grease, hot tub accesories and spa equipment will not only make your spa look good but it will optimise the use of your chemicals during a spa season.

Use spa suitable preparations when cleaning areas around hot utbs since household cleaners often contain phosphates which nurture algae growth or detergents which cause foam.
Consider a Lay-Z-Spa hot tub cleaning kit to make cleaning your spa easier.


Chemical Treatment Summary

A quick guide to products needed for treatments:
Disinfect 1 - 3 ppm (aim for 3) ClearWater Stabilised Chlorine Granules

Daily when pool in use to maintain ideal levels

pH 7.2 - 7.6 ClearWater pH Minus to reduce. ClearWater pH Plus to increase Weekly or as required to maintain ideal levels
Prevent Algae n/a ClearWater Algaecide Weekly

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