I have a Evo 13.5 and as I'm starting to add some spa pieces I've been looking into dosing. The question that runs threw my head is if I do weekly water changes is dosing needed? I know there are many factors such as bioload, and the amount of nutrients being used up by my corals. I'm sure with in a few weeks of testing I'll be able to answer my own questions but I was looking for someone's experience with the same.