what can i do to make this work?

[gmneil]

about once a month my bangaii cardinals seem to try and breed, the male stops eating and has eggs in his mouth. but the eggs never hatch and within a couple of days the male is eating food again.

i have the pair in a 10g tank plumbed into my main system.

so it can't be stress from other fish. what can i do to possibly have a chance at getting this to work?

any help would be great

thanks