Does a formula for amount of flow a tank should have exist?

Is there a guideline for how much flow you should have in your tank?  For example, "flow should = 2x tank size per hour" or something like that.  If so, what is it?  Is there such a thing as too much flow?  I know that you should have plenty of flow to make sure that it's tougher for algae to grow and to make sure that the nutrients in the water pass everything that needs them, but I'm guessing that there is a point at which you get too much flow.
I have a nano tank and my flow is 495  between my pump in the filter area of the tank and my powerhead.  At roughly 10 gallons of water capacity, that's turning over the capacity of the tank about 50 times an hour.  What I run into is that things move around so much that I'm having to turn off the powerhead for the fish to be able to get the food when I feed them.  Should I leave the flow as is and just keep turning the powerhead off when feeding, take the powerhead out, or something else?
Thanks for putting up with my noob questions.  I guarantee as I learn this stuff, they won't come nearly as frequently.  /DesktopModules/ActiveForums/themes/_default/emoticons/biggrin.gif
--AJ

 

Here's some additional details...I have a Maxi-Jet 900 in the filter area providing 230 GPH and a Hydor Koralia Nano providing 260 GPH.  On the filter pump, I have a water deflector so that I get veried water flow instead of a constant flow column (hopefully this pretty much eliminates any dead flow areas.).  I had been feeding New Life Spectrum Marine Formula food, but I switched to frozen mysis recently as they didn't seem to be able to eat the NLS granules very well...and on top of that, they float so they were quickly carried away by the surface skimmer.  I do have a sponge filter in the back, so any food that goes in there gets caught by the sponge.  Another point to add, my nano only has PCs for lighting...so that in and of itself may dictate what kind of livestock I can keep, thus dictating the flow.
All that being said, what constitutes "strong flow" or "very fast flow"?  Do I just guage it by the way that the coral behaves?
--AJ

 

I don't have the filter pump or the powerhead directly pointed at anything...with the possible exception being when the rotating deflector turns.  I have a kenya tree in there now and I see movement, but it doesn't look like it's being blown over.  The ends are open most of the time and it seems to be growing nicely.
As for the sponge, I clean it weekly with the 10% water change...every Friday.
Thanks for the feedback guys.
--AJ