I have built one and it worked wonders in my tank. It wiped my unwanted macros right out of my display. However it also started wiping out my refugium. I would suggest them to any one that has a nutrient issue or that likes to over feed like I do. However totally doing away with water changes, can not be an option. You have to have a way to replenish all of the basics in your water parameters, and without an elaborate dosing set up, I find the best way is to contiue your water changes. I also kept my skimmer running. But they do work great if you build them properly, and have good maintenance with them. The screens have to be cleaned about once a week or else they are not efficient.