How big of a pot to grow a plant in a hydro kit?

can anyone tell me the optimum size pot to grow in with hydroponics? Also can you put more than one plant in a large pot?

That is system dependant. I use 8" pots in flood and drain. Some use 3-6" net pots, some use rockwool cubes and cover them with hydrotron. Generally, nothing over one gallon size is necessary with a hydro system. VV