What is considered moderate flow?

[kjordan]

Can anyone explain it?

[bertoni]

For a 29g tank, I'd guess that 600 gph (20x the tank volume) is a reasonable guess as to what is meant by moderate flow, but there's a sad lack of quantification in most references.

[zoomfish1]

There's some awfully big words there, Jonathan. But, sounds like pretty good answer.

To put it in a visual sense, If you were looking at a coral, or an anemone, and it was waving in the water, back and forth, little more than a soft wave, that would be a moderate flow. Not really blowing it around hard, just keeping it moving. You know, moderate!

Of course, if you are looking for a general answer about moderate overall flow in the tank, then forget what I said and go with the Bertoni answer.

[papagimp]

i agree, I've had the hardest time getting the flow right in my tank because no great explanation as to what constitutes low/med/high flow. And even then, getting the right flow pattern can be even trickier. For instance, even though 600gph is 20x tank volume, it may take a couple of those to get the "flow" just right. I'd start with a 600gph and go from there.