Cal Aqua Labs "Double Check" v2

Maintaining the appropriate CO2 level is critical in a planted aquarium. Too much CO₂ may harm your fish, whereas too little CO₂ decreases plant growth and allows algae to take over.

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 reference. The top chamber holds the CO₂ indicator solution, whereas the bottom chamber carries a CO₂ reference solution. The reference solution color corresponds to 30 ppm of CO2 - a level that is widely accepted for good plant growth in most aquariums.

• Handmade from the highest quality borosilicate glass imported from Europe
• Unique dual-compartment design. Top compartment holds the Indicator solution, while the bottom compartment holds the Reference solution
• No solution preparation needed. Required solutions are premade and included
• Improved durability and ease of use
• Easy to fill and remove solutions from both chambers
• Simple to use, simple to read, higher accuracy than other single-compartment checkers

Each set includes:

• 1 Double Check v2 CO₂ checker
• 1 x 15ml Reference solution, calibrated to 30ppm CO₂
• 1 x 15ml Indicator solution
• 1 suction cup
• 2 Reference chamber plugs (not needed fort the use)

Approximate size of the CO₂ checker without suction cup: height 5,4 cm, width 4 cm (5,5 cm incl. suction cup)

Use instruction:

Open the solution bottles by twisting the cap and cutting the tip with sharp scissors. Cut below the domed tip in order to expose the opening.

Fill the bottom chamber half way with the Reference solution.

Fill the top chamber half way with Indicator solution. Tilting the device sideways and inserting bottle tip horizontally will make filling easier.

Invert checker and attach suction cup. Install checker inside aquarium about 5 cm below water surface. Make sure that air is trapped inside separating the solutions from aquarium water. Tip: Wet glass stub before fitting suction cup.

Compare the color of the Indicator solution with the Reference solution color. When the two colors are the same, optimum CO₂ level (30 ppm) is attained.