Chemical Entity

Biguanide

A chlorine-free sanitizer system using polyhexamethylene biguanide (PHMB) as the primary disinfectant.

Definition

Biguanide (sold as Baquacil, SoftSwim, and similar brands) is a chlorine-free pool sanitization system using polyhexamethylene biguanide (PHMB) as the sanitizer and hydrogen peroxide as the oxidizer. It does not interact with CYA, pH resistance is broader, and it does not bleach surfaces or swimwear. However, biguanide is incompatible with chlorine — switching between systems requires a complete water change. It is more expensive than chlorine and some users experience algae resistance issues. Not recommended for hot tubs.

Quick Facts

Ideal Range
30–50 ppm (PHMB)
Units
ppm

Relationships

No relationships defined for this entity.