PH Alert

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. Freshwater use only.

pH Alert® lasts up to 4X as long as competing products.
pH Alert® is also almost half the size of competing products. It's small, clear, and unobtrusive, so it won't detract from the view of your aquarium.