This kit comes with all you need to start reading the CO2 levels in your aquarium! It is super important to have one of these, especially if you are injecting CO2 to ensure your CO2 levels are at a safe, optimal level to grow your plants. Simply fill the drop checker halfway with the CO2 Indicator Solution, place the suction cup on the drop checker, and place it in your planted tank!
HOW TO READ YOUR CO2 DROP CHECKER:
Deep Blue Color: CO2 levels are too low (this is fine if your CO2 is supposed to be off)
Light-Green Color: Optimal CO2 levels
Yellow Color: CO2 levels too high. Add an extra airstone to add extra surface agitation or do a large water change/turn off your CO2 if you see your fish gasping at the surface for air.
When your CO2 is turned off, the drop checker solution should be a deep blue color as the CO2 will either be used by your plants or dissipate from surface agitation. After your CO2 has been on for around 2 hours, you should notice the color of the solution changing from deep blue to dark or light green. If it remains Blue then your CO2 concentration is too low and you should slowly increase it (don't go overboard!). If the color turns yellow then your levels are too high and may harm your fish.