I have kept shad alive for 8-12hrs by changing out the water in the tank. My bluewave has a semi oval baitwell and I keep a constant flow of fresh water in and trash water going out. The hose on a brick method work's without question EVERYTIME. Is it a pain in the rear...yes but so are buying and changing out filters. Imo there is no replacement for replacement of poop water with fresh water. I use keepalive and salt to purge the baits in a 5gal bucket before I put them in the baitwell. And run a big air stone to keep the o2 levels as high as possible. AMMONIA is put off by shad under stress and thats what kills the shad. Now as far as ice usage goes....too much of a temperature change will kill a shad so try not to change the water temp by more than 15�. Colder water is more dense and can hold more dissolved oxygen than warm water so it's good to keep them cool but not essential IF the water is not inundated with ammonia.

Why run a 20-50gal closed loop system when you can technically run a bazillion gallon system by just changing out the water?

Oh and a little inside tip....if you mix a quarter cup of hydrogen peroxide "which is h2o2" with 3gal of water and give your baits a 30sec dip they are so lively that they might try to bite the stripers.