The object of "flow" is to have 100% of your tank's water being moved, to alleviate dead zones of no movement.
Places of "low flow" or "no flow" in your tank may allow cyanobacteria or some algae to grow.
Water flow can be too fast for fishes or too turbulant for certain corals or can just makes feeding time harder. You can't have too much flow really, just too fast. Turning over your water 100x or 10,000x an hour is great, just as long as it's calm enough in the tank for it's inhabitants.
Places of "low flow" or "no flow" in your tank may allow cyanobacteria or some algae to grow.
Water flow can be too fast for fishes or too turbulant for certain corals or can just makes feeding time harder. You can't have too much flow really, just too fast. Turning over your water 100x or 10,000x an hour is great, just as long as it's calm enough in the tank for it's inhabitants.