So I am in the process of setting up a system that will be in the 850gallon range. I am trying to finalize the plans for my fist room but to do that I need to decide on what auto water change system I will use. My options are the Neptune DOS and the Genesis Renew. If I go the Genesis route I will need to squeeze a 65-105gallon water container into the fish room. If I do the DOS then I will just have it pull from a tank in my utility room. My goal is to change 1% of the system per day so I will do 8.5gal with the DOS or 9 gallon with the Renew. Does anyone have any experience with one or both of these that can give some input. I feel the Renew is a larger up front investment but will last longer and be more precise/less recalibrating than the DOS. The DOS gives me the benefit of more free space in the fish room moving the mixing station to another location in my basement.