Orb CO2 Drop Checker This glass aquarium CO2 pH checker, commonly referred to as a 'drop checker', is designed with a sleek, round shape that complements the minimalist aesthetic of your aquarium. Its elegant design ensures it seamlessly integrates into your aquatic environment without being obtrusive. The purpose of a CO2 drop checker To effectively monitor your CO2 levels, pair it with a drop checker solution, which is sold separately. This handy tool provides a reliable and visual way to track the carbon dioxide concentration in your tank, helping you maintain a healthy and thriving aquatic ecosystem. PH Checker key information: Non-obtrusive Easy to fill with co2 solution (sold separately here) Visually monitor CO2 levels in your aquascape Size 2.5x4.5cm Cleaning your Drop Checker Occasionally, you may notice algae or spot algae buildup on the glass of your CO2 checker. To clean it, soak the glass in a water and bleach solution for 20 minutes (using a ratio of 1 part bleach to 20 parts water) or use ADA Superge. After cleaning, be sure to rinse the glass in dechlorinated water to remove any chlorine. Then, allow it to dry; any excess water will evaporate in a warm area. Alternatively, you can use air tubing and a syringe to immediately remove any excess water.