In the second part of the series “ The story of liquid CO2 fertilisation ” we examine how glutaraldehyde containing products work on plants.
How does glutaraldehyde affect the cell and the aquarium?
Glutaraldehyde is a toxin which cross-links (fixes) the proteins on the outside of the cell membrane and thus reduces permeability. The permeability of the cell membrane is essential for the exchange of substances with the environment and also for communication between cells. It can be compared with the immune system or the nervous system of animals. When this exchange of substances becomes blocked the plant gets “paralysed” and its growth is reduced. This can lead from mild to severe manifestations and the plant can completely stop growing and die.
With small concentrations the plant can still grow, despite its weakness. With a 5 % glutaraldehyde solution concentration and a dosage of 1 ml per 50 l water daily the plant will show clear signs of damage. Comparative studies clearly show that these plants develop considerably worse than plants supplied with CO2 as their gas under same conditions. The following graph shows the results of a study to examine the increase in plant biomass within four weeks:
The “attractive“ appearance of the plants is deceptive.
The substance acts as algicide and kills algae. That will explain why the plants appear “cleaner”. But their growth has substantially slowed down and the plants even seem “preserved”. Some plant experts report that the plants completely stopped forming blossoms after they used those products. An aquarist is more likely to notice something after pruning the plants. The time it takes for them to reach the water surface becomes longer and longer and the plants don’t look healthy. To really observe the changes you will need photo documentation and experiments with several aquariums under identical conditions with the changed factor "glutaraldehyde” and the CO2 supply as gas.
You can find an outline of all the posts in the series here: The story of liquid CO2 fertilisation