FV not air tight?

[Alcopup]

Hi

did my first AG yesterday - all seemed to go well (apart from having the worst digital thermometer in the world - soon to be replaced as it made determining the mash temp very frustrating) and added the yeast (safale) to the FV last thing before going to bed - this morning there is a reasonable amount of foam on the surface of the brew - but no signs of life in the air lock (its a ritchies FV bin and a cheap air lock) - if I gently press on the lid of the bin the levels in the bubbler change as you would expect but then very rapidly equalise - which makes me think that it cannot be air tight - anyone else seen this or can offer an alternate explanation.

Cheers

Alci

[Northern Brewer]

I would not expect a clip on lid to be particularly airtight. I wouldn't worry though. If you can resist the urge, and not peek in, there will be a blanket of CO2 protecting your beer. The other side of the coin, is that in a few more hours you may have a head that's trying to escape.