Help with lighting

Hi people new to the forum wondering if anybody could advise me on what lighting to buy for a 3 x 3 grow room. I'm thinking of growing about 4 plants and buying a 250w HPS light is this enough? also I was wondering about costs, rougly how much do you think growing would add onto the average electricity bill in the UK? and finally will a fan be required for such a small op? thanks a lot in advance

sorry im not in the uk. not sure on cost. for a 3x3 a 400w hps is nice or even a 600. a 250w will certainly work if thats what you got. a circ. fan inside to keep a slight breeze. an exhaust fan with a passive intake will be needed. if temps will be a big issue you may need a cooltube.

for 3x3 or 4 (decent size) plants, the little hps will not be sufficient. I would use a 400 at the very least. 600 would be awesome. use a cool tube with the 600 and yes you should always use fans. if you don't require them for temp control, they are beneficial in growing thicker stronger plants.