Our permanent CO₂ checking solution "CO₂ Check" can be used in every permanent CO₂ testing device. It serves the purpose of controlling the CO₂ levels over a longer period of time. An optimal level of CO₂ is essential for the well-being of your waterplants and thus should be checked permanently. Our permanent CO₂ checking solution has the advatage of testing the CO₂ content independetly of the tank water so that no substances like e.g. humic acids can influence the test result. Comes in a package with a volume of 250 ml.

A pipette is included.

Fill 1 to 2 ml of our CO₂ checking solution into your permanent checking device and put it into an area with good current in your tank. After 1 to 2 hours you can see how much CO₂ there is in your tank. When the liquid is green, your aquarium has an optimal CO₂ content of approximately 20 mg/l.

A permanent CO₂ check is a very useful thing in a tank. Often the plants lack essential CO₂ and do not grow at their optimum. A permanent CO₂ check gives you a sufficiently exact reading how much CO₂ you have in your water. The colourant bromothymol blue is used here as it changes its colour with certain pH values.

CO₂ diffuses into the air bubble in the permanent test from the tank water and thus into the testing solution (and vice versa). Depending on its CO₂ content, the pH value in the testing solution changes, and with it its colour. The constant carbonate hardness in the testing solution determines which CO₂ concentration causes which pH value. The testing solution “CO₂ Check 20 mg per Liter” turns a light green when its pH is around 6.6, which corresponds to a CO₂ concentration of 20 mg/l. Thus you know that your tank water has a carbon dioxide concentration of 20 mg/l when the testing solution is a light green.