Have a new engels bait cooler. I have tried to keep minnow ovr night in it three times. First time all minnows died in less than 24 hrs. Thought maybe it was diseased minnows. Used it again and most died again in less than a day. Washed it out good with soap and water, rinsed and let dry for several days. Used again and same result. I'm using an aquarium aerator and frozen water bottle to keep cool. Have kept the bait box sealed while minnows were n it. Is there something that will disinfect this thing? Will try changing the tube and stone. Any help appreciated. Thanks