Non Chlorine Shock Granules

A weekly non-chlorine shock for hot tubs and spas. This potassium peroxymonosulfate (MPS) oxidiser clears combined chlorine or bromine and gets bathers back in within 15 minutes.

• Clears combined chlorine and bromine in 15 minutes.
• Brings back active sanitiser without adding more chlorine.
• Polishes water clarity after a heavy soak.
• Works with chlorine, bromine, MPS and salt systems.
• Safe to use just before guests arrive.

Sizes and prices

Available in 1kg, 2.5kg, 5kg, 10kg, 20kg, 25kg.

• 1kg: £18.83
• 2.5kg: £38.43
• 5kg: £71.09
• 10kg: £136.41
• 20kg: £267.06
• 25kg: £332.38

How to use

1. Test free and combined sanitiser, pH and alkalinity.
2. Confirm pH 7.2-7.6 and alkalinity 80-120 ppm.
3. Dissolve 17 g of MPS per 1000 L first in 5 L of warm tub water.
4. Set the pump to circulation and pour the solution across the surface.
5. Circulate uncovered for 15-30 minutes.
6. Retest free chlorine and bromine; get back to normal use once it is back in band.

Frequently asked questions

How often should I shock?

Once a week as routine, and after any heavy bather event as needed.

How long before I can bathe?

15 minutes with the pump running and the cover off.

Does MPS replace chlorine or bromine?

No. MPS is an oxidiser, not a residual sanitiser. Keep chlorine or bromine going for daily disinfection.

How long does a 1 kg pack last?

Around 38 weekly shocks for a 1500 L hot tub.

Is it easy on sensitive skin?

Yes. MPS forms few skin-irritant by-products and is the standard shock for sensitive bathers.

Will it work with bromine?

Yes. MPS clears combined bromine and reactivates the bromine bank for the next week.

What is MPS chemically?

Potassium peroxymonosulfate (KHSO5) at >= 47% active.

Why does MPS not raise chlorine?

MPS oxidises directly without donating chlorine atoms, so sanitiser stays at the same chlorine level after dosing.

Does MPS raise total dissolved solids?

Yes. 17 g per 1000 L adds around 12 ppm sulphate, so refresh some water if sulphate passes 300 ppm.

Combined chlorine still high?

Redose at 25 g per 1000 L; clean the cartridge overnight.

Cloudy water after shock?

Run the filter 24 hours; dose Sparkle Clarifier.

False zero on the chlorine test?

Wait 15 minutes after dosing; some DPD kits are thrown off by MPS.

MPS or chlorine shock?

MPS clears combined chlorine without raising free chlorine; a chlorine shock lifts free chlorine to 10 ppm and forces a wait before bathing.

MPS or ClO2?

MPS is a routine weekly oxidiser. ClO2 is a periodic biofilm-targeting deep clean.