Hey Dutch, I don't know if this will help but what i use i will only lose a couple of dozen, if that. I have just a regular 5 gallon bucket with a Frabill lid and a quiet bubbles aerator. Been trying to find a foam insert for the bucket to make it better insulated. The lid comes from sportsmans warehouse and fits buckets 4 1/2 - 6 gallons. The quiet bubbles comes from walmart. Runs on 2-d batteries. Runs about 36-42 hours straight. But honesty, the thing that helps the most is when i get bait, Kennny will put about 3 1/2-4 gallons of water in it. I will freeze a couple of drinking water bottles and put them in the cooler of the boat. Add them to the bucket to keep the water cool. Here is the lid so you can see it. Not sure where you are located but may find something similar.
Frabill Accessory Lid - Sportsman's Warehouse