Dave,
Thanks for the fantastic advice. My main pump is approx 980gph rated, with about 4' head ht. So it's obviously pumping less than that. I could purchase two additional powerheads to help with the flow, but i'll see how the flow is really working once i have my lights on and can see where 'things" are settling.
Also, i don't think i can get my rock off the sand because i have some large pieces and it would be extremely difficult to pick them up. I had to have two people put them in. So i don't know if that will be an issue long term. But i will definitely keep the rocks off the back.
Here's my current setup...
