when i first added my plants i still had my ancient whisper hob...i followed the suggestion to have the water level high enougn so as not to create a waterfall effect. my plants' growth have amazed me (i never had aqur.plants grow before- extremely hard water where i used to live).
anyway, i second having a spare filter. mine was so bad it took my an hour to get it to restart. then, the power went off. there we go again, and it wouldn't start at all. anyway, i was waiting on my aquaclear to arrive but for lack of anything else i purchased the cheapest filter in the meantime (i now know i never would want to use a whisper internal).
my aquaclear hob is up and running....ah, the quiet! according to the manual, reducing the flow does not reduce the filtration since it slows it down and the multi stage becomes more efficient. thoughts?
oh, it is an aquaclear 30 on a 25H tank...probably 5 gallons displaced by substrate. i have the original strip set up so it only gets 18 watts of light...things are green and i can't believe it. oh did i say growing

there is current with some surface agitation, but not much.