I agree with what has been posted above, but I think most folks don't realize that a big mandarin can eat an entire bottle of those pods in a couple days. It really is beneficial to have a sheltered area for them to reproduce AND you need to provide nutrients for the pods. Our mandarin (which is on our product label) was looking thin several months ago so I added a 40 breeder detached refugium next to my 90 display. I dose live locally cultured phytoplankton which in turns boosts the rotifer population on which the pods feed.
I keep a DSB and rubble in the corners of the fugue with a ton of calerpa and a ball of chaeto in the center. It serves as a nitrate reducing vessel and also a pod factory. When my Mandarin starts to look a little thin I will drop him in the fuge for a week or two and then transfer him back to the display.
It isn't a perfect system, because I use a Maxijet pump to push water up to the 40 breeder and then gravity drains it back into my sump. I am pretty sure the Mag 9 return pump chews up quite a bit of pods, but its the best I can do unless my son would let me put the fugue upstairs in his room, where I can let gravity drain it back into the top of the Display..LOL
For what its worth...I have successfully trained my mandarin to eat frozen food (our blend) by spot feeding it in the 40 breeder with a turkey baster when there was no other competition. It can be done, but it takes daily diligence.
Larry