Most all top skimmer are good but I prefer becket injectors =bullet aerofoamer hsa. But euroreefs, lifereef ect are good. What size skimmer and insump , hang on? What are your needs? If you run a skimmer I wouldn't worry about plankton. In most reefs i wouldn't worry either there really isn't mcuh in small aquariums. I know where to get good diy models also