Worried About Plastic Carboy Airlock Suckback

I have noticed that the water in my plastic carboy filled with apfelwein has slowly started creeping back to the point where it looks like it may be sucked back in soon... Should I remove the airlock and replace it or is this a normal occurance? I am assuming this ahs something to do with using a plastic carboy because I have never had this problem with my glass carboy.

If this means anything the apfelwein has been in there for 2 1/2 weeks...

Thanks!

If it is filled properly, it shouldn't suck back into the carboy. That being said, I use vodka in my airlocks just in case there is some suck back.

Use Star San solution or vodka in the airlock for this reason. It can happen.

It can happen, especially if you try to pick up and move the carboy. Stick with vodka and you won't have to worry when some gets pulled back into the carboy.

It'd have to cool down suddenly,usually when the krausen falls ime. This creates a partial vacuum that'll suck the airlock down low. I too use cheap grocery store vodka in my airlocks.

Use one of the s-shaped airlocks. If it sucks back it will just bubble on the wrong side.

Those things suck dry or nearly so When I used them occasionally. At least the three piece has that center cup covering the post.

Perfect, thanks for the advice guys. Purely out of interest... what does a cheap bottle of vodka cost you guys in the States? Where I am in Halifax, Nova Scotia for a pint of vodka it costs you at least $17 dollars, and you can't even go to a grocery store to buy it!

Yeesh... I get a 1.75 L bottle of cheap ass vodka for less than 10 bucks for the sole purpose of airlock filling.

"Cheap grocery store vodka" over here means the 42 proof stuff with names like Orloff. I can by a pint in a coffin flask at the BP station around the corner for $2.89 or so. No more than about 8-9 bucks a fifth.

$10 for 1.75 L .... $2.89 for a pint.... Allow me to pick my jaw back up off the floor!

For a 1.75 L of your basic Vodka/Rums/Whiskeys it is around $55 for us...

But at least we have free healthcare right!!! (Extreme Sarcasm)

I use the S-shaped airlocks and Better Bottles. When you lift a better bottle it sucks back and I have never had a problem with the S-shaped airlocks in any way--even stuff that has been allowed to age for several months.

I've never had much luck with the "S" shaped airlocks. Kinda like givin the raspberries when initial fermentation is going on/ Blows the liquid out in a heart beat. Holds less liquid then a three piece.