ESP-- if you do a websearch for my last name and microfoods, you'll find a years worth of articles on culturing phytoplanktons, rotifers, artemia, all the way up. You can get a jump on what phytoplanktons and microfood cultures for fish breeding
Instant algae is usually not alive, infact depending on which product you purchased it might be a glycerol product, or a freeze-dried product. There are a few live products (like DTs), but it s mixture and usually your culture conditions favor out growth of one of the mix.