I look at 2 factors when deciding on flow. First, I try to make it as erratic and random as possible. You can do this a number of ways but playing with the intensities throughout the day would be helpful. When possible, I run my powerheads in "reef" mode or something similar that has an irregular pulse so the flow rate is always changing. I also really like random flow generator loc-line heads. They work great and push water all over the place. Second, I focus on getting everything to "move" and not so much on what the exact flow numbers are. There are recommendations about how many gallons-per-hour the flow in a tank should be and I used to pay attention to it more than I do now. At this point I use my eyes to tell me now I should set things up. There are plenty of articles and thread about flow but your eyes really are a great diagnostic tool.
