When adjusting the direction and speed of water pumps in your aquarium, don’t just set them and walk away. Chances are, the new configuration will cause some minor issue somewhere in the aquarium, such as causing a storm of debris in the water and potentially covering corals with sand. Monitor the new changes, even if they are minor, and adjust if necessary. Eventually, the tank inhabitants will adjust to the new flow patterns and hopefully thrive because of the change. As for a time frame to monitor the aquarium after changes are made, problems don’t always manifest within a few minutes. They may happen right away, but they may also take hours to develop. So, just keep an eye on the tank for any unusual behavior and potential damage.