Air lock keeps draining?

[Guthrie]

The liquid keeps escaping from the airlock, I have taken it off and replaced it but yet again the same thing. What am I doing wrong?

 

[wSelwyn]

Can you be a bit more descriptive?

I think I know what you are talking about. Correct me if I am wrong:
The level of liquid within the air lock will change, depending on what you have inside (StarSan, Vodka, etc.). This is caused mostly by three things, as I have noticed.

The first is the liquid physically being displaced from fermentation gasses causing bubbles to rise out of the air lock, and liquid moving out of the top plastic barrier. This liquid then sits on top of the cap, and evaporates away.

The second is simple evaporation. To test this, grab a simple glass of water and set it down in your house. Mark where the original water level was, and see how quickly the level drops.

A third would be negative pressure within the fermenter, pulling the ferm lock liquid into the fermenter.

 

[krazydave]

I usually see this happen when the wort is cooling down. The temp drop creates a vacuum and sucks in the liquid from your airlock. Once fermentation starts though the co2 leaving will fix that problem

 

[Guthrie]

I think it would be the third because it's happening almost rapidly now. I fill my airlocks with potassium metabisulphite, so if it's sucking it in am I in trouble?

 

[Guthrie]

As well the wort has been cooling down, is this a common problem?

 

[krazydave]

You should be fine. The amount is so small that it shouldnt affect anything. You should just use some star-san or vodka in there from now on though.

 

[krazydave]

As well the wort has been cooling down, is this a common problem?

Yeah, it just depends how effective you were at chilling your wort after your boil. Its nice to get it down to the temp youre fermenting at, but that isnt always possible. It only takes a degree or so of drop to suck your airlock liquid in. I wouldn't worry about it...