CO2 - the basic food for your aquarium

The main nutrient for plants is carbon dioxide (CO2), which they transform during photosynthesis with the help of light energy and water into food (sugar), releasing oxygen as a by-product.

As a consequence the use of a CO2 fertiliser system is the most important way to supply your plants with food. Certainly there is CO2 dissolved in your aquarium water, but for most plants this is not enough for a vigorous growth.

If you know the carbonate hardness of your water you can read in the table shown, how much CO2 is present in your aquarium water. The green area in the table indicates what would be the ideal CO2 level for thriving plant growth or the right level for sensitive plants. Now you can see whether the CO2 content of your water is not sufficient and you need to increase it for the perfect plant growth. JBL offers you a practical JBL CO2-pH Permanent Test , which permanently displays the CO2 content of your aquarium water. This way you can easily and quickly read on a scale at any time how much CO2 is available in the water. The CO2 permanent tests always need a few hours before the CO2 content in the water is indicated. A quick and very precise method to determine the CO2 content offers the JBL CO₂ Direct Test Set . Here you add an indicator liquid into a sample of the aquarium water and you count the drops until a stable pink colouration appears. With this test you also have the opportunity to exclude other acidic effects from the test results. Simply carry out the test once more with an aerated sample and then subtract the difference between the two tests. The CO2 gas is expelled during the second test and this difference is taken into account by the subtraction.

How does the CO2 enter your aquarium water?

CO2, also referred to as carbon dioxide, is a colourless and odourless gas. It can be produced through a biological fermentation process (bio-CO2 systems) or conveniently supplied by pressurised gas cylinders. The gas is led into the aquarium by a hose and there dissolved in the water. To dissolve the CO2 in the water there are several options possible: the easiest possibility is a fine air stone from which the CO2 is released and dissolves in the water on its way to the water surface. Special ceramic air stones ( JBL ProFlora Taifun P ) create especially fine CO2 bubbles which even better and therefore more efficiently dissolve in the water. For larger aquariums of 50-400 litres the JBL ProFlora Taifun S5 2 and the JBL ProFlora Taifun M10 have been developed, in which the CO2 bubbles slowly move on a spiral into direction water surface to dissolve in the water. These diffusers can be extended with the help of modules so that an even longer reaction path is available. If you don’t want an aquarium full of technical equipment you can choose a JBL ProFlora Direct . Here the CO2 is dissolved in the water through a “direct injection” and pumped back into your aquarium by your external filter.

To increase the CO2 concentration there are fertiliser systems ( CO2 plant care ). You have the choice between bio-CO2 systems, which produce CO2 by means of a sugar-yeast system and systems with pressurised gas cylinders, filled with CO2.

You can find more about the JBL ProFlora CO2 systems here: CO2 plant fertilisation .