It is very important to have the right type of baitwell to keep scaled sardines alive all day for a productive fishing trip. To keep the scaled sardines alive you need a baitwell that consistently flushes the old water out and takes the new water in. You can do this with a GPH baitwell pump, cooler and intake and out-take.
An aerator pump is not good enough to keep these baits alive and healthy. They have kits where you can convert your cooler into a constant flow of new water in and old water out. What this does is eliminate the problems of heat and ammonia build-up, and supplies new clean oxygenated water to your bait. The water has to come in from the bottom and circulate in a circular motion.
The problem with the cooler system is that the cooler is not circular or oval. So the scaled sardines run into the squared corners and beat themselves up. You can tell by their red noses. Still if your GPH pump moves the bait in a circular direction your cooler system should work okay. Also you have to have the right GPH pump. If it is too strong, the scaled sardines will overwork themselves and get pushed around and die. It needs to be a gentle flow where they can swim gently along.
Also you need to keep the water temperatures of the water coming into the baitwell and the water already in the tank under an 8-degree variable. In other words if the water is really hot in your baitwell, say at 85 degrees, and you bring in colder water at 75 degrees, you will kill your scaled sardines or visa versa. Its a fine line -- from hot to cold, and cold to hot. It is much easier then it sounds. Just remember you need good gentle circular water flow, good oxygenated water and stable water temperatures. These things will keep your bait healthy and alive.
Captain David M Rieumont
The Online Fisherman Inc