Yes, sir – small Mysis such as the Mini Mysis by H2O Life work very well for the Red Banded Pipefish (Doryrhamphus dactyliophorus), but once the pipefish settle into your aquarium, they will not hesitate to tackle even the jumbo Piscine Energetics Mysis relicta, so they’re really very hearty eaters.
I can tell you that they do eat the Cyclop-eeze when it is presented properly so that it drifts down slowly from above right in front of them within easy striking distance (I like the frozen bars of Cyclop-eeze best for this purpose, since they will shed intact Cyclops copepods into the water as they thaw), but I would use zooplankton such as this very sparingly because there is always a lot of waste that eludes the pipefish before it settles on the bottom of the tank. (Large seahorses such as Mustangs or Sunbursts typically have no interest in the smaller zooplankton such as Cyclop-eeze because it is simply too small to elicit a feeding response.)
I have never tried the Marine Snow on the pipefish, Ray, so I cannot speak from personal experience regarding that particular project. But I imagine the results would be similar to the Cyclop-eeze, in which case it will be very important for you to use it sparingly in order to safeguard your water quality.
Best wishes with all your fishes (and invertebrates), Ray!
Pete Giwojna, Ocean Rider Tech Support