Interesting hand pump bait tank

[grey zone]

My first bait tank was a 5 gal. bucket. The overflow was made by drilling holes a few inches below the rim. I used a hand held bilge pump and zip tied the hose to the bucket so the end would stay at the bottom. A couple of pumps now and then and the bait would do fine. Spanish mackerel live very well with this type of set-up, greenbacks OK, sardines not so well.