System design

This is my system as it is currently. 
I have pressurized water coming from the pump, fed to the filter, the grow-bed, the smallfry tank and last but not the least, the duckweed tank and the mint bed.  It is quite an involved system, and it is going to get more complicated when my raceways arrive (for Deep-water culture methods).
If anything is unclear in the diagram, please ask away..