Sizing the aeration blower
The ETP blower is the machine that runs every hour, so it is the one to size hardest. Start from the diffuser submergence and the tank's oxygen demand, add the header and diffuser losses, and pick the single-stage turbine that sits at that duty point without throttling. Oversizing wastes energy continuously; undersizing starves the biology. The recommended practice is to state the design airflow and the depth of water above the diffusers so the blower is matched, not guessed, and to plan a standby unit so a service on the duty machine never risks the tank.
