Hello there Postman thanks for your reply chief....It,s good to be here mate.

Right down to buisness that link mate Ive tried it and cant make head nor tail of it,it gave me a reading of 36square foot with my room reduced to 6x6x7 leaving me a fare old space for a veg/clone room,so thats a result,what about my lights you rekon a 600+400hps,s would fit in there and 2x5" extracting either outta another window,or I might change it this time and extract thro my loft (its above my growroom),keep the suggestions coming folks,Ill start a diary once Im up and running.

Baldy.