This is the perfect size and keeps the center of gravity lower. I built one like this, but put an outlet hose in case I ever want to use it in a small row or rental boat, instead of the holes on the side. If you have a PA and you sit higher than use the next size up container. It is a lot better because it doesn't have to hold as much water as the bucket one I used before and it is all self contained with a 6v battery. I have had 15 macs in there and they do better than in the bucket tank.
http://www.kayakfishingsupplies.com/...it-tank-system