Thanks Omaha!
Your first link is the one I remembered reading recently.
I also read your second link - long ago.
[All three links contain excellent pictures of actual SMB spawning beds created by forum members.]
As to your poor SMB recruitment; I can't remember, do you also have LMB in your pond?
No LMB in my pond. SMB, YP, HSB, RES, HBG, WE (removing), GSH. I have a "shelf" on the south bank that has five beds. Placed significant amounts of rocky structure, and created a sort of "highway" towards shallower, weedier waters. Was hoping this would encourage recruitment. Still trying to get vegetation established though.