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.
pH Alert is a unique color device designed to be placed in the aquarium or filter and monitor pH continuously. A sensor changes color reversibly from yellow to orange to red alerting you to shifts in pH levels between 5.4 and 8.0. When first put in service, pH Alert response time will be about 30 minutes. Thereafter, pH shifts will register within ten minutes. Freshwater use only.