25 gal, 10 med sized cichlids, non-planted, power filter w/bio wheel, (rated for 50gal tank) 20-23 lbs of flag stone, auto feeder twice a day, setup for about a year.
I had not changed the water in about 3 weeks, but adding about 1.5 gal a week.
I had two fish die from septicemia. One fish...