There is a diffrerence between zooplankton (animal) and phyto plankaton(algae). Micro is simply a broad indication of the size of the plankton.
Many corals with small polyps need "micro" plankton and not larger varieties. Typically , most corals will benefit from zooplankton.
Filter feeders and some others will use the phytoplankton which will also feed naturaly occuring zooplankton in your tank.
Micro zooplankton includes items such as : oyster eggs, prawn eggs, cyclopeese and so forth.
You can either add the DTs directly to your tank and let it blow around or dillute it with tank water and spray it a little upstream from the organisms you wish to feed.