On monday i started my first batch, and by the evening it was going well with a good krausen and the airlock was bubbling away, but by the morning all signs of activity had ceased, at first i thought that this might have been due to slightly cold conditions so i moved it to a warmer room. But there has still been no activity since the first evening. Im sure the tub isnt leaky and i peaked inside and there isnt even a thin layer of foam on the surface. i am considering re-pitching some more yeast, but id like to get the opinions of people who know what they're doing. Thanks.