system order for raft, media bed, and nft running by gravity feed

[Sammy Steele]

Hello all:

I am new to this site but i have a question about the order of grow beds.

Mine is set up to drain from the tank into filtration system then to raft system which drains to media beds and ends up in sump where it is pumped back to tank.

I want to add nft to my system but am wondering if i should add it before my raft bed or after the media bed . My concern with after media bed is will the plants consume so much nutrients will there be enough for plants in the nft system. But if i decide to put it before the raft bed i will have to add a second pump to my set up to bring water up to it so it can flow down to the raft bed.

 

Any advice would be appreciated

Thanks 

Sam