This was when I started the process of keeping minnows.
Used a 125 gallon aquarium in my basement.
It worked just ok.
Then I moved operations out to the garage and used a large tote.
This was my final tank -
That picture was the very beginning stages.
I had built a large biological filtration system for it.
The tank was 100 gallons and easily held 1000 minnows in the winter months.
During summer months when the water warmed I had to reduce the count to below 250
The trick to keeping minnows, especially emerald shiners, is cold water and a dark environment.
Really cold!!!
34-35F
Just above freezing.
Lowers their metabolism.
They don't need to eat as much and then they don't create waste (ammonia).
Lower the stress and they will keep.
Gave it all away last year when they opened back up the bait corridors in NY.
Next project was going to be a small 5 cu ft chest freezer converted into a chilled bait tank at my place on Lake Erie.
Complete with aeration and filtration.
I never did that.
Here is a link to how to convert a large chest freezer into a fridge.
Guys do this and seal them up with aquarium silicone to hole water.
They work awesome and don't cost a ton to keep cold.
https://johnlvs2run.wordpress.com/2009/10/08/chest-fridge-conversion/#more-1061