What if you approach this from a different angle.
What if you make your cage and only put in a handful of FHM's? Maybe a couple dozen. However many could have spawning areas they could protect. Size the mesh of the cage so the breeders stay in (and anything that could eat them out) and the recruitment (babies) wanders out into your pond.
Provide cover and habitat for the fry around the cage.
Could it be you would get more breeder production that way?
That's close to exactly what I would like to do, keep the breeders in and safe while letting their fry wander out. I just would like to find the number combination that will maximize the production of young. With the one I will first put in the pond, I can start light on the numbers. With the one I put in the pool, I can gradually add more numbers to gauge how they are doing. That one can be my experiment cage and one where I can at least monitor results. I may have to set up a second pool to stock extra minnows that I can add to one or both cages over time. I plan to purchase 1000 of them as that's the unit the nearest hatchery sells them as. I first planned to use that many between the two cages but maybe that's a bad idea and starting off small is the better way to go.
Hopefully my mesh is delivered and waiting for me when I get home from work. It was supposed to be here yesterday. I want to get cracking on this and since we've been drowned by rain this past week in Missouri, the garden is far too soggy to get into and it will give me a good excuse to spend my weekend on this project.
