 Re: microplankton v. phytoplankton
Yea in the hobby thier is some debate, but in science thier isnt really. Thier are certain creatures that require phytoplankton. Ex: some clams, scallops dusters and some gorgonians. Everything else does not use them. Zooplankton is the animal form, Most all corals and critters will take these in.
Zooplankton does naturally occur i most proples reefs, but the demand on them keeps the populations low. SOme folks culture them and add them to the tank. In studies of corals, almost all coral will take detritus and waste if it is the correct size for them to ingest. Remember that when a coral say ingests a small particle of detritus its not only getting the detritus its getting all the bacteria and simular that is trying to reduce that peice of detritus. If you just think about it, the reefs in the wild have the largest fish populations in the world, yet they are the most nutrient free, the waste is going somewhere??
In my opinion all reef tanks have an over abundance of waste and detritus, more then enough to adiquitly feed corals, in most cases to much and it not only feeds the corals but also feeds algae. Adding Phytoplanton to a tank with no critters that can use it is the equal to just pouring it pure Phosphate. Rotifers could be benefical but I dont think required at all.
I have a tank with hundreds of corals and have never feed the corals, just the fish. Now thier are some corals that may require external food. Corals such as the ones with large amounts of tissue (tissue needs nutrient) If these corals show signs of thinning tissue then I would suggest directly feeding them.
Keeping a reef tank is always a battle with to many nutrients, adding more for no reason can prove costly.
Mike | 
