I don’t know exactly when the cyanobacteria infestation began. In the laboratory journal I mentioned them for the first time on April 3, 2020.

They became a serious nuisance and I spent a lot of time curbing their proliferation. In an aquarium shop, the above preparation was recommended to me after a water test showed that the reason for their exorbitant increase was not due to a too high a silicate content in the water.