Can i give blood if i smoke cannabis?

Hi guys just wondering if i can give blood because i smoke cannabis, i mean dnt think im a bum who stays at home all day on the dole smoking i am a tutor and i have a spliff every night b4 bed maybe a little more some days but it is only to relax myself everyone i work with will go home and have 1 gl to halfd a bootle of wine after work but instead i choose a bifda, so i am well aware of the consequences but would i be turned away from giving blood.