I used to raise fish maybe 20 years ago, now I just don't have the time. They are not hard to raise but they require a lot of time as you need to feed them continousely, not once a day like adults and you need to change their water every day because you can't really put a filter in there as many of the fry are this big -----------> . <------------- (cute isn't she?
As for tips on breeding mandarins it is the same with all fish, you need to feed them and feed them a lot. I invented a mandarin feeder and it is on here someplace. I put new born brine shrimp in there every day to supplement the many pods in my tank. I also give them some live worms every day. They especially love white worms because they remain alive for hours in salt water. It is difficult to collect the eggs as they spawn early in the morning and you need to be there exactly when it happens and they do it in the back of the tank. I would keep them in a separate tank and try it or at least try to put them in a separate tank when they are ready but that may get them out of the mood. Mandarins are not easy to convince to spawn when you want them to spawn. You can do that with clownfish but mandarins are stubborn