Ok, time to improvise. Take a rubber made sweater box or similar container, add an airline, weighted down plastic plants or a home meade breeding mop, float that sucker in the tank with the other fish and let them spawn. Once you see the fish driving themselves into the plants or mop they are spawning. When they start hunting and pecking they are eating the spawn and need to go home. I would add a small sponge filter once the eggs are laid. You can actually start it with an air line in the community tank.
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