I deployed my homemade oxygen system this weekend and I learned a ton. On Saturday I put oxygen on the fish at about 11:00 and kept is running on low till weigh in at 3:00. Because of all the dead fish in the weigh in line on Friday I experimented and boosted the oxygen level for about 15 min before we went to weigh in line. Our 7 fish were in perfect health when we handed them over after weighing even though I had no oxygen or anything on the them in the line. I am amazed at how much oxygen does to keep fish alive.