well in a 10 x 10 it depends on how much room you like to have....I have 4 600w lamps set up with a 4' square spot for each which ends up being 8' sq. that only leaves you with 1' arround the outside to walk arround IMO not enough room but it dose depend on how much room your gona let the plants take up....just think about it before you jump into it....here is a little pic for you. the lights are 4 600w agrosun red bubls ran off of lumitec electronic balasts (240v)....later DH