difference between an Ebb and Flow
 

Does anyone know the difference between an Ebb and Flow system, and Hydroponics, ? and which one would be better for indoor growing of African Violets and Poppies, with a 1500 watt metal halide light source

Ebb and Flow (aka) Flood and Drain is a kind of hydroponics. Just as NFT (nutrient film technique), Aeroponics, Drip emitter systems are all forms of hydroponics. Any system where plants are grown without soil could be considered hydroponics.