Lay-Z-Spa chemicals
Lay-Z-Spa chemicals come down to chlorine to keep the water clean, plus pH and alkalinity adjusters, sized for tubs of 160 to 314 gallons, or 605 to 1,190 litres. A shock for a Miami AirJet takes about 0.35 oz of dichlor (10 g), and the tub gains 3 to 4°F an hour (that is 1.5 to 2°C).
- AirJet range, smallest to largest
- 160 to 314 gal (605 to 1,190 L)
- Target level for free chlorine
- 3 to 5 ppm
- Miami 177 gal shock dose
- 10 g (0.35 oz)
- Heat-up rate, Miami
- 3 to 4°F/h (1.5 to 2°C)
Gallons and chemicals for each Lay-Z-Spa model
The Lay-Z-Spa AirJet manual lists each tub's seat count, its water volume and its heating rate. We based the shock column on 1 oz per 500 gallons from the EPA dichlor label, so larger tubs need a larger scoop.
| Model | Persons | Gallons (litres) | Shock dose, dichlor | Heat-up an hour |
|---|---|---|---|---|
| St Lucia | 2 to 3 | 160 gal (605 L) | 0.32 oz (9 g) | 3°F to 4°F (1.5°C to 2°C) |
| Miami, Cancun, Bahamas, Tahiti, Bali | 2 to 4 | 177 gal (669 L) | 10 g (0.35 oz) | 3°F to 4°F (1.5°C to 2°C) |
| Vegas | 4 to 6 | 205 gal (775 L) | 0.41 oz (12 g) | 3°F to 4°F (1.5°C to 2°C) |
| Ibiza | 4 to 6 | 205 gal (778 L) | 0.41 oz (12 g) | 3°F to 4°F (1.5°C to 2°C) |
| Paris | 4 to 6 | 213 gal (806 L) | 0.43 oz (12 g) | 3°F to 4°F (1.5°C to 2°C) |
| Hawaii | 4 to 6 | 222 gal (840 L) | 0.44 oz (13 g) | 3°F to 4°F (1.5°C to 2°C) |
| New York EnergySense | 4 to 6 | 240 gal (908 L) | 0.48 oz (14 g) | Not listed |
| Palm Springs, Honolulu | 4 to 6 | 242 gal (916 L) | 0.48 oz (14 g) | 3°F to 4°F (1.5°C to 2°C) |
| Helsinki | 5 to 7 | 297 gal (1,123 L) | 0.59 oz (17 g) | 2°F to 3°F (1°C to 1.5°C) |
| St Moritz | 5 to 7 | 314 gal (1,190 L) | 0.63 oz (18 g) | 2°F to 3°F (1°C to 1.5°C) |
For ClearWater granules, the Lay-Z-Spa chlorine dosage chart uses 20 g per 1,000 litres, which equals 13 g in a 669 litre tub. Because brands vary in granule strength, go by the label on the chlorine container. Although that chart shows the Miami at 800 litres, both the manual and the Miami product page list 669 litres (177 gallons).
How much chlorine does a Lay-Z-Spa need?
Keep free chlorine between 3 and 5 ppm (parts per million), says the Lay-Z-Spa chemicals guide. At least 3 ppm is what the CDC asks for in any hot tub. Aiming for 3 to 4 ppm meets all three standards since the printed AirJet manual specifies 2 to 4 ppm. Here is the routine from the guide:
- Identify how many litres you have. Search for your model name since water volume determines the dose.
- Apply granules to shock the water. After mixing granules into warm water in a jug and pouring it in, spread it around by running the AirJets for a few minutes.
- Let a day pass, then test. Lay-Z-Spa asks that you wait at least 24 hours after a shock. Use a test strip to check for 3 to 5 ppm.
- Balance chemicals in the right order. Start with alkalinity at 80 to 120 ppm. Next, adjust pH to 7.2 to 7.6. Add chlorine last. Allow at least 2 hours between each chemical application.
- Use tablets to hold the level. Place slow tablets inside the floating dispenser. The manual states that granules do not belong in it. Take the floating dispenser out before anyone enters the water.
The chart lists a top-up rate of 9 g per 1,000 litres for ClearWater granules, or 6 g if you have a Miami. Stay out of the water if your test strip shows more than 5 ppm. Lay-Z-Spa advises draining some water and adding fresh water to lower the level.
Tablets or granules must never be dropped straight into the tub. They sink to the floor, stain the PVC and damage the liner, the manual warns.
Time needed for Lay-Z-Spa to heat up
Most AirJet tubs warm up 3 to 4°F each hour, or 1.5 to 2°C, per the owner's manual. Helsinki and St Moritz, the two largest tubs, manage 2 to 3°F, that is 1 to 1.5°C. The heating help page from Lay-Z-Spa applies that slower rate to all tubs and notes a cold fill may require 24 to 48 hours.
These are the times the AirJet manual lists to reach 104°F (40°C) when air and fill water start at the same temperature:
| Starting temperature | Time to 104°F (40°C) |
|---|---|
| 50°F (10°C) | 16 to 24 hours |
| 59°F (15°C) | 12 to 20 hours |
| 68°F (20°C) | 10 to 18 hours |
| 77°F (25°C) | 8 to 12 hours |
| 86°F (30°C) | 5 to 8 hours |
The Miami page estimates 6 to 12 hours during a typical UK summer day. The heater on the pump draws 2,050 W. Before you check the water's true temperature, let the filter run for a minute or more. See hot tub heat-up times for other heaters and tub sizes.
Cost to run a Lay-Z-Spa
Daily costs for its tubs in the UK are £0.60 to £1.70, or £18 to £50 a month, says Lay-Z-Spa. Its test used a Miami AirJet at a rate of 24.67p per kWh (kilowatt hour). The water was kept between 38 and 40°C (100 and 104°F), with the AirJets running for 1.5 hours in spring or autumn weather.
| Lay-Z-Spa type | Cost a week |
|---|---|
| Regular inflatable | £9 to £12 |
| Regular, with thermal cover and floor mat | £6 to £8 |
| EnergySense inflatable | £5 to £7 |
| EnergySense, with cover and mat | £4 to £5.50 |
| ThermaCore foam wall | £4.50 to £6 |
| ThermaCore, with cover and mat | £3.50 to £5 |
Starting from cold water increases heating costs significantly. In summer, a full week in a regular tub from cold tap water cost £15.34, while winter cost £20.31 in the same tests. Lay-Z-Spa notes that keeping the heater set steady costs less than cooling and reheating if you soak 3 or more times weekly on separate days.
See monthly hot tub running costs for the kWh figures and prices in the US, Canada and the UK.
Common questions
What amount of chlorine goes into a Lay-Z-Spa?
For a Miami (177 gallons, 669 litres), a shock calls for about 0.35 oz (which is 10 g) of dichlor, or your product's label dose. After that, keep free chlorine between 3 and 5 ppm using slow tablets placed in the floating dispenser.
What is the gallon capacity of a Lay-Z-Spa?
St Lucia starts the AirJet range at 160 gallons (605 litres) and St Moritz ends it at 314 gallons (1,190 litres). A Miami takes 177 gallons (669 litres), and a Helsinki 297 gallons (1,123 litres).
What is the heating time for a Lay-Z-Spa?
Reaching 104°F (40°C) from 68°F (20°C) takes 10 to 18 hours according to the manual. Allow 16 to 24 hours if starting from 50°F (10°C).
Do you need ClearWater chemicals for a Lay-Z-Spa?
No. Although Lay-Z-Spa recommends ClearWater and builds charts around it, any spa chlorine, pH, or alkalinity product works if used at its own label dose. Test the water before every soak.