filters measured with an inline flow meter to flow just about what theyre rated (give or take a couple of GPH
depending on the individual impeller).
i have a tank running 60x turnover/hr (thats 1 turnover a minute for my math friends) and its running perfectly.
i also have a 40g with a 450 gph
sump and 2x 500gph HOB
, and there is no added stress to the inhabitants.