Biguanide is a chlorine-free sanitizer such as Baquacil® Chlorine-Free Swimming Pool Sanitizer and Algistat, BaquaSpa™ Sanitizer, SoftSwim™ Bactericide, PolyClearr® MaxiPolish Swimming Pool Sanitizer and Algistat, or Revacil® Swimming Pool Sanitizer.*

AquaChek™ Blue is a simple-to-use two-part test:
Step 1 — dip the strip and check the Total Alkalinity and pH
Step 2 — re-dip the strip, moving it back and forth underwater for 30 seconds, to test the Biguanide level

To keep your pool or spa water at its best, test at least once a week, and write down results so you can track changes over time.

Comes with complete instructions in 15 languages: English, French, Spanish, Italian, Czech, Danish, Dutch, German, Greek, Hungarian, Polish, Portuguese, Russian, Swedish and Turkish.