setting up a refugium for max pod production

I have a 55 gallon display tank on the first floor of my house. I'm building a 55 gallon refugium in my basement.



The water from upstairs will enter the tank in a section with a small pump for water changes then flow control baffles then a section with plants then baffles and to the last section with the return pump.



I plan to fill the last portion with live rock rubble.



I also plan to set a over flow next to the last section going to a 30 gallon tank filled with live rock rubble.



I have two questions related to this project.



1 being that the 30 gallon tank is primarily for pod production what kind of flow rate do I want to maximize the production of pods going to my main tank?



2 how much live rock do I need in order to produce enough pods for a wrasse and two dragonets? In other words how much rock per dragonets is needed?



Thanks in advance for your advice.