What would you say is a safe amount of time you can keep a fish in a sealed bag for?
I guess it depends on size, but lets say a 7cm pretty round fish, e.g. a gourami.
if they are going to be kept in a bag for a day or so the only reason being is thats how long it takes for transportation so if its known they will be in a bag for that length of time then there is usually oxygen added and the fish are starved for 24-36 hours so they don't foul the water and be killed by ammonia. if no precautions are taken then i would say about 4-5 hours is long enough
I wondered this at times since most often when I get to the lfs I'm in that area for other shopping and that part of town is set up horribly, with bad traffic to add to it. So I always go to the fish store last since I don't want me fish in the car forever since it's a 15 minute drive home after I'm out tof the shopping district.