need more grow area info to help.is the area heated,garage or living space if your in a heated garage with 12 foot ceilings don't bother with a tent use the money on a light instead. Its easier to control the environment in a room than a room and the tent in the room.plus easier to get around plants to move them and water them.you can just put some white poly around the grow area no higher than your going to have the lights at.then your heat will escape under,around and over the poly and help heat your garage area.mount the poly so you can just slide it out of the way when you want to.But with 12 foot ceilings if the room is big enough heat will not matter you can use whatever you want.I just set up a new area in my 16x20 man cave -work shop with 3-315 cmh over a 4x8 table and i love it so far still early yet.I also have 12 foot ceiling in the middle and 8 foot side wall.best of luck to you.Oh dont let anyone tell you you have to use only a certain light. you can get great results with several, like kgp said the inexpensive hps will grow you great buds and have been for a long time and give you good wattage options.Its more about learning to get the most out of what you have and getting familiar with that.
give it 12 hours of darkness and if your in a room where you cannot do that then yes you will need a tent or something you do not want to be coming in the room and turning on the lights during dark period.not to mention the smell later.a small bedroom your going to have to be careful with heat.If this is your first grow you may want to just go with cfl or t5 lights to keep your bedroom inhabitable.if you got the coin then led would work great now and later.there is no reason why your plants will not do well,just remember your in a bedroom you will find out what I mean by that as you grow.P.S. dont do anything permanent now only temporary and as you learn and decide you want to continue growing then you can determine what you want based upon your own experience and best suits your grow area.Best of luck you will love this hobby.dont I need a tent to give it 10 hours of consecutive complete darkness to flower??
give it 12 hours of darkness and if your in a room where you cannot do that then yes you will need a tent or something you do not want to be coming in the room and turning on the lights during dark period.not to mention the smell later.a small bedroom your going to have to be careful with heat.If this is your first grow you may want to just go with cfl or t5 lights to keep your bedroom inhabitable.if you got the coin then led would work great now and later.there is no reason why your plants will not do well,just remember your in a bedroom you will find out what I mean by that as you grow.P.S. dont do anything permanent now only temporary and as you learn and decide you want to continue growing then you can determine what you want based upon your own experience and best suits your grow area.Best of luck you will love this hobby.