Depending on where you are, I don't think just keeping the water in a container is enough to condition the water. You'll also need to provide a little more information as well. Answering a few questions will provide you with the best feedback.
Did it come from tap, a pond, stream, well...etc?
What size tank is this? what filtration are you using?
How long have they (the one now) been in the tank?
Last but not least, Did you cycle your tank?
All that aside and assuming all your water parameters are within reason, it is common for Gouramis to breath air at the surface. They have the same labyrinth organ as the Betta, but it sounds like something is wrong with your water. I would suggest testing Ammonia, Nitrite, Nitrate, Water Temp and PH it to make sure. Also Gouramis can be territorial and aggressive and should be kept with similar fish of the same temperament.
Someone hear should be able to help you. Lots of great advice here
Last edited by Fishhook; 08-10-2014 at 03:00 AM.
55 Gallon Native Species: Bluegill, mosquito fish, fathead minnows
29 Gallon: Pearl Gourami, Brilliant Rasbora, Bristle Nose
10 Gallon: Beta, Clown Pleco