you'll never be able to rear larval fish in a tank with other fish, adult omnivorous inverts.
also, most filters are good at eating larvae.
If your parent pair are in good spawning condition, they'll spawn again in as early as 2 weeks. If you're interested in getting serious on rearing, time to start culturing phytoplankton and rotifers... you might be ready in 2 to 3 spawnings from now. Good luck.
Time to check this out:
http://www.fao.org/docrep/003/W3732E/W3732E00.HTM