Dymax produces a wide range of plant equipment down from fertilizer to instruments. To ensure they are most efficient and best in quality, the products have gone through strict quality control and efficiency examination. With all the standards we demanded, the user will have the assurance of our products and their highest achievements.Never fail to monitor your CO2 & PH levels in aquarium by using this indicator. Monitoring co2 levels in your planted aquarium is very important for the health of your plants and fish. This kit is complete with everything that you will need. It includes: High quality drop checker and suction cup.EXTREMELY EASY TO USE CO2 DROP CHECKERTo use simply fill the drop checker half way with the Co2 Indicator Solution. Place suction cup on the drop checker and place in your planted tank. Wait 2 hours to read Co2 levels.HOW TO READ CO2 DROP CHECKERWhen your co2 is off the drop checker solution will be a deep blue color. After co2 has been on for around 2 hours you should notice the color change. Optimal co2 concentration will be at 30ppm which will be a green-light green color. If it remains blue your co2 is too low. If the color turns yellow then your levels are too high and may harm your fish.