Ammonia Alert's® sensor changes reversibly from yellow to green to blue, relative to the ammonia concentration. It detects less than 0.05 mg/L (ppm) free ammonia and alerts you to the #1 killer before any sign of stress. The presence of the free ammonia is detectable continuously with a response time of about 15 minutes. Response to decreasing ammonia is slower, requiring about 4 hours to go from TOXIC to SAFE on removal of ammonia. Marine or freshwater use.

Key Features:

• When first put in service, pH Alert® response time will be about 30 minutes.
• Thereafter, pH shifts will register within ten minutes.
• At 1.5" x 2.5", they are small, clear, and unobtrusive, so they won't detract from the view of your aquarium.
• Simply place Ammonia Alert® visibly towards the bottom of the aquarium (as ammonia is heavier than water).
• It’s that easy.
• No chemicals or test procedures are required.