Not just any minnows, but those emerald shiners. You know, the ones that start dying before you even launch the boat after buying them at the bait shop or netting them yourself! I'm sort of on a mission to having my own stock of live minnows ready to fish with.

So I have a funny story, I go back to the foot of ferry to net some more minnows. I brought another new bucket with me, do you remember my story of the last time, where the knot untied and the bucket floated away? Anyway, I bring a small bucket to get water, and my larger 20 gallon bucket that's designed to keep bait alive. It has an aerator with it, a dc powered one designed to run off of a car battery. I get a bunch of minnows, and probably 10 gallons of some sparkling niagara river water in my vehicle, and fire up the aerator. Everything works, and this coming from equipment that has been sitting on a shelf, never used, for at least 10 years probably more. I make it home, about 40 minutes, and check on my minnows, they are all alive! Nice! I disconnect the battery, and bring my bucket inside, down into the basement. Note to self: maybe not so much water next time. So in the short amount of time it took me to get the bucket inside and down in the basement, I see about a dozen minnows belly up inside. Just like that. So I connect my aerator again, this time on an ac adapter. Check in half hour, all minnows are back alive. Even the belly up ones, they revived. Yes! Check the next day, all minnows look great, hardly any hanging around the top of the water which is a good sign. On day 2, I get home from work and my wife says, "what's that smell downstairs?". Now I knew that a little paint thinner had gotten on to the basement floor so I told her that was probably it, and in all honesty that's what I thought it was. So I head downstairs to check and as soon as I opened the door I smell dead fish! Uh oh this doesn't look good. I go check on the minnows, they are all dead! All of them! Thank goodness I live in the country, sort of, and put those puppies in my big compost pile. Nice rancid minnow water, lovely smell haha.

So here is what I think I did wrong:
1) I had the bucket sealed up tight (it's able to do that). Even though the aerator was working properly, what I am finding out is that minnows produce nitrogen as a waste gas, and this needs to be vented.
2) In addition to aerating, I have to use some type of filter, to filter out the waste products.

I think what happened was the ammonia, nitrogen, etc that got generated from the minnows eventually just built up in the water until it became toxic and just wiped them out.

Anybody keep their own minnows alive?