Suction Cup & Silicone Plug for Cal Aqua Labs - Double Check

One replacement suction cup and silicone plug for Cal Aqua Labs Pearl CO2 Drop Checker

One replacement suction cup and silicone plug for Cal Aqua Labs Oracle CO2 Drop Checker

Pack of 2 replacement suction cups for all Cal Aqua Labs drop checkers and filter pipes.

Cal Aqua Labs' Double Check series is the only all-glass dual-compartment CO2 checker that allows the user to accurately compare the CO2 level in your aquarium side-by-side against a standard...

CAL AQUA's Double Counter functions as both a normal-flow and high-flow bubble counter in one elegant design. Normal-Flow Configuration: For small to medium sized aquariums where CO2 bubble rates are...