I have a Fluva 305 and 405 on this tank. (I always double up filters on my tanks) even though it's only a 40 breeder. I don't know the answer to your question about vals and current, but I've always had vals in a position where they're buffetted by the outflow with no issues. My bigger issue with vals in this tank is that one of the male peacocks takes umbrage at vals being planted behind his "house," i.e. the piece of wood to the right, so he is always uprooting them! :lol: