I have had a rbta in my reef tank for over a year. I have a lot of softies and LPS. I have always ran activated carbon. I run a bag under my overflow pad, change it monthly. No other chemical filtration but I use a skimmer. I keep my water as perfect as possible with 10g water change weekly(tank 37g) It is very happy and healthy has grown very large, waiting and hoping for it to split but it has not and I take that as a good sigh.