This summer I kegged a pale ale for the first time. For about the first week or so the carbonation level on the beer was great but then the beer started to get flat (still tasted good, just no bubbles). I carbonated with priming sugar.
Once the beer started getting I did the "soap test", putting soapy water at all the connection points on the C02 canister, keg, and lines. There were no bubbles so I don't think I have a leak, this conclusion is (I think) backed up by the fact that the C02 canister is holding at a steady level.
I don't have a kegerator so the keg was kept in my garage at a temp between 65-75F. I'm using a corny keg with ball locks. Prior to kegging I replaced all the o rings on the keg.
I really enjoyed the ease of kegging and would like to continue doing it but I'd like to figure out what I did to cause my beer to go flat so I don't do it again.
What's causing my beer to go flat? A leak (how should I test for it)? Is the relatively high storage temperature to blame? I'm really at a loss and would love some insight.
EDIT
Sounds like my problem is incorrect pressure for my storage temp. I'm planning to get a kegerator early next year to put this to the test.