Aqua Rebell CO2 Check 20mg, 250 ml

CO2 is essential for healthy plant growth in the aquarium. However, a CO2 level that is too high can be dangerous for aquarium inhabitants, so it is important to monitor the CO2 level with a long-term test to ensure that it doesn't accummulate in excessive amounts.

You can fill any CO2 long-term test with the test solutions Aqua Rebell CO2 Check 20 mg/L and Aqua Rebell CO2 Check 30 mg/L and thus keep an eye on the CO2 level in your aquarium water. The ready-to-use test solution can accurately detect the CO2 level in your aquarium water regardless of any discoloration of humic acids present in it.

The Aqua Rebell CO2-Check long-term test liquid is available in a 250 ml container. Fill the CO2 tester with 1-2 ml Aqua Rebell CO2-Check test solution. Next place the tester in a spot in your aquarium where there is good water circulation. The CO2 from the water diffuses into the test liquid via the air bubble and changes the pH there. This is visible as a colour change after 1 to 2 hours. The colour of the active ingredient bromthymol blue adapts to the pH. Yellow indicates a CO2 level that is too high and blue indicates a CO2 level that is too low in aquarium water.

If the test liquid turns green, the CO2 content of your aquarium water is acceptable. The acceptable CO2 content for Aqua Rebell CO2 Check 20 mg/L test solution is 20 mg/L. The acceptable CO2 content for Aqua Rebell CO2 Check 30 mg/L test solution is 30 mg/L. We recommend the solution for 20 mg/L for all community aquariums and aquariums housing invertebrates. We recommend the solution for 30 mg/L for aquariums with CO2-hungry plants or for aquascapes with good lighting and in which aquatic plants have plenty of nutrients available.

Our expert Oliver Knott recommends:
Aquarium plants need CO2 to grow and thrive. However, too much CO2 is not good. The Aqua Rebell CO2 Check test solution helps you keep an eye on the CO2 level in your aquarium water.