According to the manufacturer’s recommendation, the preparation* should be applied over the course of 5 consecutive days and then, as a preventive measure, once a week. At first the treatment with the preparation was quite successful, but then the cyanobacteria developed splendidly again. I decided that the only way to solve the problem was to dismantle the aquarium and relocate the fish.
I was prepared and already equipped a new fish tank [see image housing situation]