water changes benefit more then just reducing ammonia, nitrite, nitrate etc....they also replenish the natural balance of the water. salt water as it ages loses its purity...Protein skimmers help "scrub" the water of fine contaminates and such. on your tank it is not essential, but of course would never hurt. id bet, that despite his tank being "nice" it is likely an unhealthy habitat. dont follow his steps, do the 2 gallon a week water change and save yourself the hassel with algae and such.