Hi, new on here full of questions.. I grow up the loft, insulated and sheeted. I got myself some cool tubes and with advice, set up a pipe from the out side. through a fan, pushing the air through the tubes then outside. problem is even with one light out (I have 3, 600w hps) with this, hot weather we are getting, in scotland, it's still going up to 32c. bit hot. I don't put my lights on till 9pm and of at 9am, trying to keep to the cooler times. my questions are, is this the best way and how powerful should my fan be... thanks.