Excerpted from Kodiak and commented on by Capt Patrick McCrary.


"Technical Bulletin # 695 Larry E. Wilkin
Questions and Answers on Live Bait Tanks

Here are some frequently asked questions about live bait tanks. These questions are asked by users across the country and apply to most bait fish in general.

Q. Why are round and oblong tanks best for keeping bait fish?

A. Fin fish used for bait naturally school in a circular pattern, so round and oblong tanks are the best choice. Sea World, The Monterey Bay Aquarium, and Scrips all design and build their tanks round or oblong. These shapes provide the most efficient use of space. Fish held in square or rectangular tanks will round off the corners when they school and swim in a round pattern in a square tank and oblong pattern in rectangular tank. At best the corners become wasted space unused by the fish, at worst the fish become trapped in the corners and suffer as a result.

-- My livewell meets this requirement - CPM

Q.Will bait fish live longer in a tall tank or lower profile tank?

A. Both will keep your bait alive, and both have disadvantages. The tall tanks popular in California take up less deck space and slosh less. Although low profile tanks may be prone to sloshing, they provide more room for fish to school. Many species of bait fish will migrate to the bottom half of the tank despite its height, so a low profile tank will give the fish more area in which to swim. At Kodiak we make both. My suggestion is buy a tall tank if you fish in areas where sea conditions or the size of your boat would make a lower, longer tank slosh.

-- My livewell meets this requirement - CPM

Q. I can’t seem to keep bait alive for very long, WHY?

A. This is probably the most frequently asked question I get from anglers from Maine to Florida to California. Although water flow, temperature, tank shape, ammonia buildup and other factors dictate how long bait will survive in captivity, the number one reason for premature death in bait fish is mechanical abrasion. Mechanical abrasion simply put, is anything that removes scales or slime from fish. Removal of this protective layer causes what Marine biologist call death due to "Osmotic regulation" more simply, the fish dies due to dehydration. When fish loose slime and scales they dehydrate thru their skin, to counteract the dehydration they take in more water, in the case of salt water species this includes salt. This unusually high intake of salt causes kidney failure and the fish die. That is why fish that don’t lose scales will last longer than fish that do.

Q. What can I do to prevent this?

A. There are many steps you can take to reduce mechanical abrasion:

1. Don’t overcrowd your tank. While you may start the trip with more bait, they will have a much higher collision rate against other fish and be forced against the walls thus losing more scales. What you will have to fish with will be disappointing.

2. Don’t mix species of bait. The larger hardy bait will impact the fragile bait that will lose scales, die and fall to the bottom of the tank. The scales free floating in the tank will get into the gills of the hardier bait killing them.

3. If cast netting bait or jigging try to avoid touching the bait with your hands. Using a cast net causes scale loss but emptying it onto the deck then picking up the bait to put it into the tank is even worse. Empty the net into the tank if possible. Use a butter knife to remove fish from bait jigs. Slip the dull side of the knife under the hook and shake the fish off into the tank avoiding contact.

4. When buying bait from a commercial bait provider ask him not to scoop too many fish at once. Crowding the net causes the bait at the bottom to be packed and loose scales. Ask how long he has had the bait, generally the bait he has had the longest will be in the best shape. This is called cured bait, the bait damaged when first caught will have died and the remaining will generally be in good shape.

5. Plumb your tank correctly. It is important to insure that the volume of water is sufficient to flush out impurities and keep the oxygen high. As to the question, "Do I put the water in at the top of the tank or bottom?". Both create problems. A powerful stream emitted by an undamped feed line below water level can strip scales, and cause bait to panic in an attempt to dodge the flow. Installing spray bars or 90 degree fittings to direct the water against a side wall causes problems with fish impacting the fittings. Water entering above the water line eliminates these problems, but if the drain is also at the top stagnant water and ammonia may build up at the bottom of the tank. The best way to introduce water is thru a water baffle plate that is flush to the tank wall, and introduces water thru slots evenly over the entire water column. It is important that there are enough slots to reduce turbulence and that the slots are cut at an angle to create a directional water flow inside the tank. Directional water flow tanks help the bait school while providing more oxygen over there gills. However you chose to plumb your tank, "Keep It Clean." Spray bars, exposed fitting, drains or other plumbing pipes that the fish will rub against all lead to scale loss and premature bait death.

6. Fill time, or the time it takes the tank to fill to the overflow fitting. A good starting fill time is 5 to 8 minutes, then adjust for conditions. Most attention to this subject has been directed at turbulence from too fast fill time. Although turbulence or too strong a current in a tank is not desirable, neither is depleted oxygen (O2) content nor the build up of ammonium from fish excretions. Cold water holds more O2 than warm water, so anglers that fish in warm water areas must increase flow to keep O2 levels up. If your bait fish are gasping for water, they need more O2, so you need to increase flow. Ammonium build up is another factor, the more bait and the type of bait you are using will effect the ammonium build up. It is imperative to keep the level low for healthy fish. Increase flow when carrying more bait. A tip for reducing ammonium. When you first fill the tank, the fish will excrete more from the stress. Open the bottom drain cap for a few minutes allowing the tank to drain from both the top and bottom to flush the tank out faster. Be sure to watch the water level.

-- My livewell will meet this requirement when fitted with flow valve after the pump - CPM

7. Another important factor relating to water flow is keeping fresh water free of air bubbles. If you are getting cloudy water or see air bubbles coming in thru your intake line check to see if the intake strainer on the bottom of your boat is picking up turbulent water from a forward mounted transducer, a propeller, or hull chine.

8. Use a small light at night to illuminate your tank. This will prevent fish from crashing into the walls and each other. The light will also sooth the fish and make them less spooky at night. Large scale marine aquariums do not turn off all the lights at night for this reason. Look into the tank at night, if you can see the bait they can see each other and the walls. The light source can be built-in or a small deck light that will shine through the tank.

-- My livewell can be made to meet this requirement - CPM

9. Don’t install the drain too far down from the top of the tank. This can cause excessive sloshing, which is hard on the bait. At Kodiak we install our drain fittings 2 3/4" down from the top of the tank.

10. Rough tank interiors cause scale loss. Fiberglass tanks may look great from the outside but will injure bait fish that rub against their rough interiors. If you insist on fiberglass go to the additional expense of a double walled tank, in the long run it will be worth it.

-- My livewell meets this requirement - CPM

11. When you remove bait from the tank don’t dig the net deep into the tank. This can injure the other fish. If your friends are diggers let them catch the bait by hand. Hand nets that fall into and are left in the tank are murder on bait fish, again causing scale loss.

12. Finally, don’t beat up your bait by going too fast. Pounding across waves or even small chop can cause sloshing in your tank that will rub scales off. You may get there first, with dead bait.

Q. Why a bait pump, don’t aerators work?

A. Aerators supply only a limited amount of O2 to the water. They cannot maintain the level of O2 saturation in the water that you can achieve by pumping in raw seawater. They do not remove harmful ammonium or foam from the water. Water temperature can rise thus reducing its O2 level further and the increased water temperature can cook your bait. When used for long periods nitrogen will also build up in the water, causing build up in the blood of the fish. Who needs these problems? Fresh water in, old water out, is much easier and better for your bait.

Q. Do I need to add chemical conditioners to my bait?

A. I have had little experience using these products since their main use is in closed aerator systems. If you are supplying fresh water all the time while constantly discharging the old, they won’t stay in the system very long and I feel they are not needed.

Q. What about bottom drain tanks (reverse flow)?

A. This type tank drains from the bottom, the water then goes up an exterior mounted stand pipe which establishes the water level. You will see this design used in the marine aquarium field. The name for this type of plumbing is called a "Hartford Loop." When designed properly they remove fecal matter and scales from the bottom of the tank. The problem with using this design on free standing live well is that in order for the system to work properly the bottom of the tank must be coned like a funnel and the drain at the bottom must be large enough to prevent clogging from dead fish that fall to the bottom. Coned bottoms do not sit flat and are therefore not feasible for free standing live wells. Attempts have been made to duplicate this self cleaning design using a flat bottom tank with the drain on the side wall, at the bottom. However to create the required suction and pull scales out a minimal amount of drain slots are used, and they tend to clog badly. If a few dead fish or squid eggs get sucked up against the drain the slots will clog and the tank will over flow out the top. If you are designing a tank that will be inside an enclosure the coned shaped bottom and Hartford Loop drain works well.

-- My livewell can be made to meet this requirement - CPM

Q. What about hand wells, windows and tops?

A. Hand wells are common on larger tanks. They allow you to hold a few bait fish at a time instead of dipping the net in every time you need bait. Smaller tanks lack the room to adequately provide for a splash rim around them and the water and bait slosh out and end up on the deck. Windows are impressive, your guests can see the bait inside the tank but may harm the bait if they bump their noses trying to swim out. -- (I concur whole hartedly!) - CPM Tops or covers are a must for keeping birds out. They also help keep the water in the tank in rough seas. A poly board cover also makes a handy cutting surface.

Q. Do I need to mount my tank permanently? I hate drilling holes in my boat.

A. Holding a tank in place mechanically is preferred, you never know when you may run into bad weather and sea conditions. A tank containing several hundred pounds of water rolling around your boat is dangerous. But, if you insist on no holes, strap it in, or empty it when sea conditions warrant. Scoot Guard is a matting material available in most RV and boat stores that can be used to reduce sliding. When laid on a fiberglass deck under a full tank it will be almost impossible to slide. This material works best with low profile tanks with a low center of gravity that will not tip over. Another option for boats with a swim step or platform, is to use an extension board. Kodiak sells extension boards to fit its tanks that are designed to use a clamping arrangement requiring no drilled holes.

Q. Can I glue my polyethylene plastic tank?

A. NO, the polyethylene used for most plastic tanks cannot be glued. The base material contains paraffin or wax and nothing will stick. Fittings can be installed using a process called spin welding. A hole is drilled or routed in the tank and a pipe fitting of the same material is then spun in at high speed. The two objects melt together due to the heat generated by friction and become one. The only other way to mend polyethylene is a process called hot air welding. Marine sealants can be used to seal holes that have screws in them, from mounting rod holders or other add on’s. The sealant prevents the hole from leaking but does not bond to it.

Q. I own a plastic polyethylene tank, what maintenance does it require?

A. Another advantage of polyethylene over fiberglass is that it needs no waxing. Nor will it chip, rot, or get spider web cracks These tanks are impervious to gas and oil. The same material is used for making boat gas tanks. Washing with the same soap that you use on your boat is all that is needed. Stains can be removed using a non abrasive cleaner like Soft Scrub with bleach. If you notice algae starting to form on the inside of the tank, it can be removed by closing off the water intake hose, filling the tank with water and adding a ½ cup of household bleach. Let the tank stand over night and it will be algae free in the morning.

A good quality polyethylene tank should last 10 years or more, if the manufacturer uses material that has a high UV rating, also call "enviormental stress crack rating." At Kodiak we use the highest rated UV treated material available. UV, or sunlight is the only thing that is detrimental to polyethylene. Covering the tank when not in use can double its life. A simple cover can be a large size trash bag with a bungee cord to hold it on.

Q. Why should I buy a Kodiak Pro Flow when others are available for less money?

A. A product is worth what it does not what you pay for it. Pro Flow tanks were designed after years of research on what works for keeping small bait fish alive in captivity. We spent countless hours with the professionals in the marine aquarium industry and long range charter boat skippers asking for their ideas. The result was the development of a live well bait tank that does what no other can, provide the optimum captive environment for your bait fish. Our patented directional flow water inlet system, no clog drain, built in light dome and rounded shapes all combine to keep your bait alive. Providing the satisfaction of arriving at the fishing grounds with a tank full of hot bait and then watching line disappear from your reel as you hookup to the fish of a life time."