I will give you my take.
More air is helpful, but most likely not your first problem. Try these
1. Fewer fish, (maybe 10). Overcrowding fish, no mater the O2 content, will
stress fish.
2. NO ICE. two problems, a rapid change to the cold of even a few degrees
can cause problems, in this case warm is better then cold. Second, it would
be almost impossible (almost) to get ice without chlorine, and that will
kill them quick.
3. to reduce stress, cover them with a blanket or something like that, the
dark will calm them, reduce their activity and stress and cause them to use
far less O2.

Good luck

"JMH" wrote in message
.. .

I have a pond behind my house with a few catfish. I have a friend with a
well stocked pond and am in the process of taking some fish from his pond
and putting them in mine. I usually transport 20-25 at a time at a
distance of 35 miles (takes about 45 minutes). The are transported in the
back of my SUV. These fish are caught with a rod and reel, I only keep
the
ones hooked in the mouth.

The fish are 1, 2 and 3 pound fish. Currently I have a small 20-60 gallon
Aquarium Air Pump with dual hoses that I run on a battery pack into a 45
gallon plastic storage container with a lid. I put some ice, but not very
much to cool the water.

Today, I moved about 20 fish, but three died in transit (not a real
problem, I will eat them tonight!). I am worried about the others I put
in
the water though. They swam off pretty good, but I want to give them the
best chance to survive.

Can anyone give me hints on the best way to keep these fish alive? Should
I use more ice to cool the water more? Do I need a bigger container?
Anyone have any suggestions for a bigger container? Do I need more
airflow
than the small aerator I have?

Any hints would be appreciated.

Thanks!