As I posted you have to use a very good Aerator to keep Herring Alive. I use this one
http://www.marinemetal.com/products/.../power-bubbles
The battery operated cheap ones will not do the Job and they will die.
If I am planning on keeping them for an extend period of time I place them Large Bucket and have the bait shop fill it to the top and then add a scoop of the Blue Stuff they use for the bait. I will change the water with Cold Well Water the next day only if I have to keep then longer and use a cooler instead of the bucket. I never have any issues the key is to keep them in a lot of water that is very aerated. Good Luck
