I've used both Wiess, but the sand filters will clog and are hard to restart if you stop the flow, like when cleaning a filter. I now use a 600gph dedicated pump for the sand filter with 2 ball valves to control filter flow and the excess flow goes back into the tank. My main/show tank has 3 magnums in parellel pulling water from 3 inlets, filtering, going through a 40 watt UV sterilizer, then valved out to 2 outlets and 1 sand filter. With this setup I can shut down 1 filter at a time to clean it without having to totally stop the flow.
