Hi Asa
Charles Matthews here. I found a letter from you, and I remember some conversations we have had in the past. I hope that you got some reply from me- if not, you are welcome to call.
I have a lot of respect for you. You are an obviously talented design guy. I suspect you will ber able to make a significant contribution to NPS husbandry particularly in designing optimum flow regimes. I'd like to correspond with you about that part, which I think needs development. I may be that we get a manufacturer enlisted in your design work who can implement it for the general market.
Some thoughts: from long experience, I would disconnect your concerns about nutrient management from the flow issue. I worked with the EcoWheel large area algae scrubber for years, and feel a Chaetomorpha form is easier and, indeed, more effective. I know you love your algae scrubber- I think I really had a romance with mine- but in the end, I replaced the scrubber box with Chaetomorpha and it works much better. The Chaeto outpaced the algae scrubber when I ran them concurrently, and the algae scrubber essentially stopped producing. Somehow, Chuck's phosphates stay under control; after trying everything (from Vodka to Lanthanum!) I now use a large amount of Warner Marine's large granule phosphate remover; it doesn't clog with the heavy feedings. I put a lot of it in my Deltec sump skimmer. When nitrates go lower, I can turn down the air to the skimmer and increase the flow through the GFO.
Regarding nitrates, I would think of those separately. I think the Miracle Mud people have a great system, the fine beds denitrify beautifully. In fact, I think they way to go may very well be a large Miracle Mud filter for denitrifycation plus GFO, keep phosphates undetectable, and then feed continuously with a syringe pump pump to keep nitrates detectable (that is, feed sufficiently to keep nitrates in slight excess of use by the system). That's currently where I am going with my large system. If you think about the nutrients this way, it simplifies the problem of getting optimum flow, and you can concentrate on how to get wonderful laminar flow.
Regarding flow, I would work on the problem of laminar flow, rather than surge- there's some good surge options out there, but no laminar option.
You and I have much in common
Charles Matthews M.D.