What flow rate adjustment is needed for a commercial building with a sand filter of 1000 GPD?

For a commercial building utilizing a sand filter with a capacity of 1000 gallons per day (GPD), the adjustment of the flow rate is critical to ensure optimal performance and compliance with the system's specifications. The correct choice indicates a flow rate of 250 gallons delivered four times a day, which sums to 1000 gallons daily.

This flow rate adjustment is important for maintaining the efficiency of the sand filter, as it allows for sufficient time for the filter media to process and treat the wastewater effectively. By spreading the flow rate evenly throughout the day, the system can function within its designed parameters without becoming overloaded, preventing issues like clogging or inadequate treatment of effluent.

The other options, while presenting different gallon adjustments, do not align with the ideal flow rate necessary for balancing treatment needs and system capacity. If the flow is either too high at certain intervals or insufficiently distributed, it can lead to inefficiencies or malfunction of the treatment system. Thus, the specified adjustment of 250 gallons four times per day is the optimal choice for maintaining a properly functioning sand filter in a commercial context.