Keeping Your Bait Alive

Introduction

This simplified guide is intended to teach the fundamentals of the proper aeration techniques in keeping live bait, and "catch & release" fish, alive and healthy in live wells.

The advantages as well as disadvantages of many types of aeration will be discussed.

Understanding the Concept of Aeration

There are many misconceived ideas about aeration.

Two common fallacies are:

Large live wells are required to sustain a large quantity of fish.
Large live well pumps are needed to move large quantities of water through the live well to keep live bait and fish alive.

To understand what is really needed in proper aeration, it is best to take a look at ourselves.

FACTS:

If we were enclosed in a large airtight room we would be able to breathe for many hours before we would consume all the oxygen.
If we were in an airtight closet, the oxygen would be consumed a lot quicker.
If we were swimming underwater without a snorkel, the oxygen in our lungs would be gone very quickly.
In all cases, without additional oxygen we would expire!

However, we could stay alive indefinitely, if we could use a breathing tube or snorkel that was in contact with outside fresh air or oxygen. It would not matter about the size of the container that enclosed us.

An aerator is to a fish, what a snorkel is to us!

Size of Aerators and Snorkels

FACTS:

It is more difficult to breathe through a straw than through a large snorkel.
A small or ineffective aerator cannot provide as much oxygen in the water as a larger or more effective one.
If an aerator can provide enough oxygen in the water for the fish to breathe, it doesn't matter how much water surrounds the fish! The only reason that water must be changed occasionally in live wells is to remove ammonia caused by fish poop!

Basic Requirements of Aeration

There are two major considerations in aeration:

The gentleness and direction of water flow
The size and amount of the air bubbles

Gentleness and direction of Water Flow

Delicate bait such as shad, greenbacks, and white bait will not survive a day of fishing unless the water flow in the livewell is soft and gentle. Turbulent water will damage the bait and force them to work against the current.

Ideal water flow within a live well should be approximately 1 to 2 MPH. And in a circular motion. This will allow fish to school and provide a smooth flow of water over and through their gills. If the water flow is excessive, bait will tire quickly and will not be lively.

Size and Amount of Air Bubbles

Take a look at the air bubbles produced by an aquarium aerator. Watch how quickly the bubbles rise to the surface. They provide little aeration, but are aesthetically pleasing to watch. Bubbles must remain contacting the water, if they are to do the job properly. A good rule of thumb is: The smaller the bubble, the longer it will remain suspended in water to dissolve.

A Lesson in Air Bubbles

The smaller the air bubble, the more slowly it will rise, giving it more time to dissolve in the water.

Due to the higher density of salt water, air bubbles are usually smaller in salt water than in fresh water.

A large 20mm bubble has a volume of 4.19 cm³, and a surface area of 12.6 cm².

You could make 260 small 3mm bubbles from the large bubble. They would have a total surface area of 83.6 cm². This is 6.6 times the surface of the 20mm bubble.

The small bubbles, can theoretically aerate 6.6 times as much water with the same amount of air.

Knowing the importance of air bubble size, the effectiveness of different aerator systems becomes readily apparent!

Livewells

Livewells come in many shapes and sizes. Oval or round tanks provide the best circulation. However, rectangular or square wells are satisfactory if there is a directional discharge into the well. The directional discharge will induce the more desirable circular motion.

Spray Bar Aerators

Spray bar aerators add oxygen to the water by jetting small streams of water into the surface. Some air is absorbed into the spray as it passes from the spray bar to the water surface, and when the spray strikes the water surface, air bubbles are injected into the water. For the most part, these bubbles are rather large.

Jets of water from spray bars are generally harsh to delicate bait. Their protective coating and scales are easily removed, and their survival is drastically reduced.

Spray bars are an inefficient aeration system, and should be used only on the hardiest bait.

Air Stone Aerators

Air stone aerators are an inexpensive way to keep bait alive in small containers. They are quiet and gentle, but because their bubbles are typically larger, they need a greater amount of bubbles for a large amount of bait.

Air stone aerators do provide gentle aeration, but they sustain less bait per unit of air than aerators that produce smaller bubbles.

Venturi Aerators

This is the much copied, old aeration technology. They can be purchased as a floating aerator or a bottom aerator with suction cups.

The fast-moving water at the output of the pump creates a vacuum, which suck air into the pump output. This system typically provides larger amounts of smaller air bubbles than previously discussed aerators.

Some models damage bait due to the high speed of water from the pump output.

Thru-Hull Pumps

Thru-hull pumps provide a constant flow of new water into the livewell and eliminate the problems of heat and ammonia build-up. As long as clean water is available, more bait can be placed in a given amount of water than with any of the previously discussed systems. However, when entering water that is less than ideal for delicate bait, care must be taken to secure the intake water. By utilizing a combination of the thru-hull pump with other aeration methods, bait can remain healthy and lively for longer periods of time.

This article was brought to you by KeepAlive™ Oxygen Infusion Systems. We would also like to give special thanks to Bob Heideman, President of Aquatic Eco-Systems, Inc., for providing us with his expertise in aeration.

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