Glass Co2 Indicator Aquarium with Suction

Ensure the best water condition for your pet fishes with this Glass Co2 Indicator Aquarium with Suction! It is easy to use and very practical! All you have to do is mount this device on the inside of your fish tank using the suction cup it comes with. The bulb holds C02 and it indicates the levels by means of changing color. Blue means low, yellow means high, and green means there just enough CO2 in the water. Also, it is of high borosilicate glass which is non-toxic and durable.