thanks for the advice man. so by plain soil/perlite mix do u mean multipurpose compost/perlite or just plain topsoil/perlite? im a complete noob at this so sorry if these questions sound stupid.

Also about the wring of the light; im assumiing the power to my house is running on a/c because there is one mains cable coming into the garage directly connected to a double socket.Attached to the double socket are 2 cables leading into the attic. im assuming that one of these is connecting the ceiling flrs to each other and the other is returning the current to the mains. so if i turned off the mains, spliced the wire in between the 2 ceiling flrs and connected a socket, would i be in business?

And with the venting, im gonna hook up an inline fan and flexihose leading to the soffit vent to extract the air. as far as air intake goes, would u suggest buying another fan for this (funds are running low at the mo) or is there cheaper method ie. CO2 tablets etc.
thanks again 4 the advice and looking forward to any input:thumbsup::smokin: