TJ, bad news about your pond! I was hoping you and others could keep a good population of grass shrimp going.

I know mine are gone as well and I just blame the lack of any vegetation. I know I can blame crayfish but I can't catch any in traps so I doubt I have very many crayfish. My gold fish took the blame but I have reduced numbers from 500+ to about 50 or less and still no vegetation.

I think my soilfloc applications play a role now as the bottom is like concrete and I don't know how easily plants and seeds can establish.

I'm sure a bare bones bottom to the pond gives no hiding places for the shrimp. I'm trying to keep some FA in the shallows for them to have a place to hide.

I'm starting the SFS journey too and will be putting some artificial structure in (I made 4 structures, 2 with stacks of CDs and 2 with stacks of plastic cardboard) I'm going to try to add some logs and maybe some riprap as well.

I wonder if I drilled some depressions (on an angle and straight in the pipe without going all the way through, even some longer slots in the plastic?) the side wall of a plastic PVC pipe if the SFS would use them.

keep us posted if you find the reason for the floating vegetation.