Small amounts of salt is also very helpful and like many have said always keep frozen bottles in ur cooler every little bit helps we kept a 7 pounder alive two weeks from 6 a.m. to 2 p.m. it was the first fish we caught and all we did was recirculate the water that was in the livewell and towards the end of the day we placed a bottle of ice in there and when we put the fish back in he was alive and well the outside temperature was 92 with no wind and no clouds so it was definitely hot. None of the little treatment packs were used just treat your fish in a respectful manner and check on em through out the day and do what you think is necessary to catch a fish they will only die if no oxygen is provided!!!!