I threw all my fish into the same tank...2 of my RD's paired up and I now have a couple hundred fry that I have removed and put into a seperate tank...as other above have said, just let them be and if you get a pair, they'll breed on there own
I am feeding the fry Hikari First Bites...they seem to be enjoying it...when they get a little bigger, I will feed them some small brine shrimp as well...