As you mentioned, FHM lay their eggs on the under side of things. They also lay them on hard substrate, so I would assume the carpet would be a poor choice, but the experts might have a different opinion on that. Now other minnow species that lay their eggs on top the carpet might work well. I don't really know.

I have heard of FHM's using a red Solo cup for a spawning site in a pond, so about anything that is a hard substrate and has an underside in the depth range that the FHM's need, they will use as for spawning as desired.

The male also protects the eggs so areas that are easily protected I would guess would look good to a FHM. Like a foot long piece of 2-3" pvc pipe.

So whatever you might have laying around that you don't mind being on the bottom of your pond that meets the criteria above will probably work.

Shallower water will warm quicker so spawning will start earlier, but if you have bird predation very bad some structure in a little deeper water, like 3', will give some later or more protected spawning sites.

Just my ideas, worth what you paid for them. I'm no expert.

John

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