I had issues hauling crawfish for pond stocking until I figured out what I had to do differently. If you are transporting them to cook and eat the next day or two, it's completely different than stocking in a pond. I even tried to haul them like I did fish and that didn't work. They crawled on top of the diffusers and I had O2 issues in the tank. The fine bubbles turned to coarse bubbles and wouldn't transfer enough O2 to the water.