I set this system up in our kitchen last year to help hone my skills of growing lettuce and herbs using a 50 gal reservoir with the plans of switching to a 50 gal fish tank this year.  Just getting ready now  make that move, and trying to figure out what kind of filtering system would be best.  I used coco 3" cups in the gutters when doing "hydroponics" and I am wondering if I should switch to the clay in the gutters and add earthworms.  Am I barking up the wrong tree? Any advice out there?…