I added yeast to my carboy Saturday afternoon, and the airlock blew off sometime Sunday while I was out. I think the reason is I added too much yeast. When I discovered it, I just assumed the batch was spoiled, and I left the airlock off the carboy. A fellow brewer told me it should be OK as long as I put the airlock back on. It is now Tuesday morning, and I’ve added the airlock back to the carboy, but my question is: should the batch be OK, or should I dump it?
Dump is a 4 letter word 
It will probably be fine. Even with the airlock off, the active fermentation is blowing co2 out the hole so nothing was going to get in. Ferment it out, bottle, and drink. No sense dumping now when it may be fine…you can always dump later.
I usually don’t use an airlock on primary fermentation at all. Just some aluminum foil to cover the carboy “neck” to keep things from falling in. I’ve had too many airlocks blow off and make a mess of the ceiling.
Your comment about adding too much yeast is probably off the mark and you should be happy to have such an active fermentation. No worries.
I never use fermentation locks since I practice “open fermentation”. Several solutions for you: try reducing the volume of wort in your carboy by a half gallon and/or use a blow-off tube. Another is to put a few drops of Fermcap in the fermenter when it starts to show foam.
Thanks for the advice. I’ve put the airlock back on and it is bubbling away.