ro is def not a waste of time and money basically your goal in setting up a marine enviroment is water quality, the better the water the healthier your system can get to.ro water is great for those new to the hobby and for those wanting a low nutrient system.if your new then go with an ro unit it will help take some of the frustrations out of the hobby, if you must use tap water be sure to use prime when mixing new salt batches and top off water
welcome to te hobby any questions just shoot