This is how I got my green mandarin to eat
frozen brine shrimp and cyclopeeze. I bought a medium size Lee's breeding container from Petsmart (about $5.00). I added a couple of small rocks and put mandarin in.
I then culture some live
baby brine shrimp and feed to mandarin. I freeze the left overs. After about a week of feeding live baby brine shrimps, I start to feed my mandarin the left over dead frozen baby brine shrimps. By this time, my mandarin is use to eating brine shrimp and it's welling to eat the frozen ones. After it's eating frozen baby brine shrimp, I mix in some cyclopeeze. After a while, I will feed only cyclopeeze.
I think the most important thing in getting your mandarin to eat frozen food is
to put your mandarin in a confine space with low water flow where you can slowly introduce the food and let the mandarin pick and poke at it until it knows that it's food.
My Lee's breeding container with mandarin was in a 10 gallon with minimum water flow. This is so the baby brine shrimp doesn't get blown everywhere when introduce to the mandarin.
Beng