No, it is not. If you feel you need to feed pods you can use pellets or flakes which are much cheaper and pods eat them. They do not need or even eat phytoplankton.
Pods will multiply depending on how much food there is, but any food will do. They are not picky and you can't even stop them from reproducing as long as you have enough food in the tank. They normally live on uneaten food that the fish leave so there is normally no need to feed them directly.