In a tank with different protozoa populations, what action should you take if Stalked Ciliates make up 20%, Nematodes 20%, and Rotifers 60%?

In a situation where the populations of different protozoa in a tank are primarily composed of Rotifers (60%), with Stalked Ciliates and Nematodes each at 20%, the appropriate action is to increase the waste activated sludge (WAS).

Rotifers, which make up the majority of the protozoan population, are generally more effective at consuming organic matter and are indicative of good settling characteristics in the sludge. However, a predominance of Rotifers alongside a balanced distribution of Stalked Ciliates and Nematodes can suggest an imbalance in the microbial community or excess organic loading. Increasing the WAS helps to manage and control these populations, ensuring that the system doesn't get overloaded and maintaining a healthier balance among the microorganisms.

Moreover, by increasing WAS, you can remove excess biomass from the system and improve overall treatment effectiveness. This helps in maintaining optimal operating conditions in the tank, which is crucial in wastewater treatment processes to ensure efficient removal of contaminants.