well now it just seems to be one... really it is when i am in the grow roomt hat it seems to do this. i think it might be a loose connection or somehting shitty like that.. anyhow it is on for now. it seems to have a very slight flicker. i only notice it whne i look at the light cast on the wall in an adjoining room, when i look right at the light the flicker is imperceivable.