I added a power head to my 75 today. Instead of let it run 24/7, I plugged it to a timer making it run on and off at different time to see if the corals like it. Some mechanical timers can do the same.
This tank was started about 6 years ago, use a 10 g tank to hide the skimmer and heater. A Yellow Tang was put in the tank a month ago to clean up the caulerpa that grows like crazy.