I use a 55 gallon drum tilted on its side. Also have the KeepAlive system and the LARGE filter. Works great. I can keep about 30 herring for maybe 2 days with good upkeep.
I use Foam Off which keeps the foam ... well... "Off"
I also use "Pogie Saver" which calms the fish and helps keep their color. Believe it or not, 2 years ago, prior to pogie saver, I was having a little luck, not much, with my "Faded" herring. I stopped in and saw mike for more supplies and he gave me some Pogie Saver to try. Heck of a lot better....eyes stayed nice & clear. Without it, they eyes fogged up and looked very unnatural.
Just keep up with them and you'll be fine. I rotate water every few hours......12 hours maybe. Drain some scales out and add some new water.