15 g per m³ drops pH approximately 0.2. Always pre-dissolve and retest before re-dosing.

Will it drop alkalinity?

Yes, by about 10 ppm per 15 g per m³. Adjust pH and TA in sequence rather than chasing both at once.

Can I use vinegar or lemon juice?

No. Both are organic acids that feed bacteria. Use proper dry acid only.

How long does a pack last?

5 kg lasts a typical 40 m³ pool around 4-6 months of weekly correction.

Is it the same as muriatic acid?

Same job, much safer to handle. Sodium bisulphate is a granule; muriatic acid is fuming hydrochloric.

What is the active ingredient?

Sodium bisulphate (NaHSO4) at 95% purity.

How does it differ from hydrochloric acid?

Dry acid is a granule that dissolves to release H+ slowly; hydrochloric is a liquid that releases H+ instantly. Same end effect, very different handling risk.

Why does it drop alkalinity?

Bisulphate ion reacts with carbonate buffer; both pH and TA fall in proportion.

Lift back with pH Plus; retest in 4 hours.

Lift TA with sodium bicarbonate first, then correct pH.

Dry acid vs liquid acid?

Dry acid is safer to store, ship and dose; liquid hydrochloric is cheaper per ppm but generates fumes and burns skin instantly.

pH Minus drops pH; pH Plus lifts it. Use whichever fits the test reading; never both at once.

Pool pH Minus - Sodium Bisulphate

Name: Pool pH Minus - Sodium Bisulphate
Brand: ClearSpa
SKU: pb-2
Availability: InStock
Rating: 5.0 (7 reviews)

Sodium bisulphate dry-acid pH Minus for swimming pools. The safer alternative to muriatic acid, dropping pH 0.2 per 15 g per m³ in clean granule form, no decanting and no fumes.

Drops pH approximately 0.2 per 15 g per m³.
Drops total alkalinity approximately 10 ppm per 15 g per m³.
Replaces hazardous liquid hydrochloric acid with a clean granule.
Restores chlorine effectiveness when pH has crept above 7.8.
Stops calcium scale forming on heaters and tile lines.