I don't have a lot of experience with this new hobby, but I noticed that germinating seeds in a similar aquaponic environment may produce good results and reduces the shock of transplant.
Black-eyed peas were germinating in a plate with kitchen towels, hydroton, and water from the fish tank.
When transplanted, I noticed how clean the roots were. Not to mention, the sprouts were easy to move from the plate to the grow bed
Transplanted from the plate, into the grow bed
This seed was planted in the grow bed, just to compare.