Quote Originally Posted by canebreaker View Post
Hardin's fish farm is south of Calhoun City, MS. Next time at Grenada or close I get a few pounds to use. I'm seeing a few pickle barrels on marketplace, about half of a 55 gallon barrel. They have removable lids. Should be good for a few days camp and fish trip.
I use to use crushed oyster shells from the feed store in a container with a overflow installed as a filter medium. It worked very well. I had the smallest pond pump Lowes sold down in the bottom of my tank circulating the water up to the container with the crushed shells allowing the water to return by falling from above into the tank with some splash. The falling water allowed ammonia to evaporate into the air helping to remove it from the water. A bacteria grows on the shells that consumes the ammonia & nitrogen added to the water by the shiners. I went to the Koi Filter but my water quality really didn't improve over the oyster shell filter system.

That said you have to expect die off unless you use a ammonia treatment or partial water changes until the bacteria has time enough to grow. Usually 2-3 weeks for a good colony big enough to clean the water.