I have tried a feeding post before But found that the best way to fee them is to just dump the mysis and let them " hunt" for it, however this always caused some problems with food remaining.
With the feeder I just dump the block on the top and it will gradually disperse through the hoes as it melts.
I find there is a bit of time before they notice food so as it defrosts it starts to slowly release a few and then accelerate when they are in full hunting mode! Will try it out for the next few weeks.