Thanks for the information. I feel better now.
I thought there had to be holes to let the ammonia escape. It just warmed up enough in the last couple weeks to be able to thaw the 5 inches of ice. In another month, without any water moving I don't think I would be able to break the ice.
I have a tank that is plenty big enough for them to be able to go into, so that isn't a problem. I just didn't know how long to give them to acclimate before feeding them.