? CONTROLS AMOUNT OF CO2 IN YOUR TANK WATER --- The Rhinox CO2 Bubble Counter is used in conjunction with the Rhinox CO2 Diffuser Set that accurately measures carbon dioxide flow rate and controls its level in your aquarium water. The inbuilt check valve restrains water backflow. The transparent plastic that the counter is made of makes it easy to see the bubbles; so you can effectively determine the bubbles per second. ? HEALTHIER ENVIRONMENT FOR YOUR FISH & PLANTS --- Overactive or deficient amount of carbon dioxide in your tank can cause undue stress on your fish and plants. Too much of it in the water can cause the pH levels to drop. A fully functioning CO2 system with a Rhinox DIY Bubble Counter gives you brighter, faster-growing plants, and happier and healthier aquatic pets. ? BETTER THAN OTHER ALTERNATIVES --- Certain types of fish and aquatic plants (such as glosso and bunch plants) thrive in habitats with a higher level of CO2 in their water. Liquid treatments such as CO2 boosters and even simple additives like baking soda can have adverse effects. Adding a CO2 diffuser and bubble counter to your aquarium setup is an effective way to add the required amount of gas. ? INSTALLS IN SECONDS WITHOUT INTRUSION --- The Bubble Counter is ideal for a 2 to 5 gallons aquarium. Quick and easy to set up, the high-quality DIY Bubble Counter simply connects to your current CO2 diffuser tube. Fill the bubble counter with water, attach it to the tube and then use the included suction cup to securely fasten it to the outside wall of your aquarium. Being outside of your tank, there is no distraction from the beauty of your underwater environment. ? EASY TO READ ACCURATE WATER LEVEL --- Once the equipment is installed and attached, it is time to count the bubbles. A solid black line against the transparent vessel clearly indicates how much water you should put into your CO2 regulator. It should be filled at just below the black line. Having the correct amount of water in your bubble counter is essential to accurately count the bubbles and determine the amount of CO2 in your tank water.