How well has the barrier in the wicking bed been working so far? Meaning, have you noticed any sediment building up in the fish tank at all?

I tried to put worms in my clay pellets. I don't know if it did anything, but I figured if any escaped it'd just be a treat for the fish.

Sounds like you've got good results so far. Looking forward to seeing how full those beds are in about three months from now.