Mrs. Eva Rambo, who fishes CM and CUSA was a science teacher for 40 + years and she says that oxyegen will keep fish alive longer than cooler water. Her reccomendation is to use hydrogen proxide in the water. This will add oxyegen to the water. I usually put a couple of ounces in the water periodically. I haven't had a problem yet. She has yet to explain how it works but it does.