Kayak Bait Tank Project



Cost :  Under $60.00 with the battery possible, more if you like, less than $40 if you leave off a couple things.

Time Required:  Getting parts, 2 hours  Building, 1/2 hour while watching Discovery Wings.

Tools / Skills Required:  1/2" wood bit, 1" wood bit, 1 5/16" wood bit.  The one inch and five sixteenth bit is hard to find unless you live near a "real" tool store.  Places like Home Depot etc. jump from 1 1/4" to 1 3/8".  If you have a metal cutting bi-metal set using mandrels, you can buy a 1 5/16 cutter for $7.99 at Home Depot etc.  The mandrel costs $17.99 OUCH!

I used a 1 3/8" wood bit and ground the sides to make it bore a skinny hole.  You could also wrap tape around the hose to fatten it, seal around it with goop, or just not worry about it.  This is for the exhaust on the tank, and you don't even need to put a hose on it if you don't mind the water cascading noisily down the side of the tank.  I fished twice at La Jolla and put my 1 liter water bottles under the flow to keep them cool before I added the hose system.

No special skills needed, but you might drill a hole or two in the middle of the lid to get a feel for the wood bit on plastic.

Pretty simple, huh?  And you don't even need the hose on the right...

Items needed:

1.  Tank of some sort that fits in your kayak.  I used a 5 gallon bucket, but lots of plastic containers to choose from at Wall Mart, find one that you like.

2.  Pump.  You want a BAIT AERATOR pump, not  a bilge pump.  They are nearly the same, except the aerator pumps are available with a "straight thread thru-hull attachment".  That's the one.  I used a Rule Pro-Series 360 GPH Aerator Pump with some extra features, like detachable head to clean the impellor.  A better deal would be to go to Wall Mart and buy the Attwood 500 aerator pump for $16.99.  Half the cost of mine and should work just as well.  Just make sure it is the one hanging in the bubble-pack that looks like the one in the picture here.

3.  While you are at Wall Mart also buy a brass./rubber drain plug, right next to the aerators, 1/2 inch hole, two for three dollars.  If you don't have a battery buy a 6volt lantern battery for $5.99, or be cheapo and buy the $2.00 one, but I don't know how long that one is good for, the better one will run your tank up to 12 hours, maybe more.

4.  Now go to the hardware store and get the plumbing as follows:

a.  two feet of 1" ID washer hose

b.  one 1" right angle PVC Schedule 40 elbow, slip fitting style  The 1" is the ID of the pipe that fits it.

c.  one garden hose to 3/4 id hose barb adapter.

5.  Next go to West Marine or similar and buy a "Plastic In-Line Non-Return Valve" with 3/4 OD hose barbs on both sides.  This stupid part cost $14.99, almost as much as the pump at Wall Mart, but it allows you to prime the pump easily without awkward bulbs with extra hose and junk, AND then will hold prime if you turn off the pump for a while, and then turn it back on.  Important to me!  The one I'm using is branded "Whale" and is part number LV 1219.  They have a website at whalepumps.com.   A better idea may be to look in the "drip irrigation section of OSH or Home Depot or where-ever you buy the other hardware items from and get a check valve (called and anti-siphon valve) there.  They come in several styles in bubble-packs and cost $2.99-$4.99.

6.  Last go to Kragen's, Pep Boys, or whatever and buy a car PCV right angle elbow for 3/4" hose, and buy a foot of 3/4" ID radiator hose.



Ok let's roll...


We'll build the sub- assemblies first, starting with the pump/intake set-up.  The pump's threaded part is the right size to thread onto a garden hose bib, which is really convenient as you should have bought an adapter at the hardware store to go from the pump to a 3/4"OD barb.  Cut a 2" piece of 3/4" radiator hose, push it onto the barb, then push on the check-valve as shown.  Look at the flow arrow. You can now use this assembly to gage the different heights and places you can install this on the tank, and reach a scupper hole or part of the tank well that always has an inch or more of water in it.  Ideally you will stick the end of the check valve into a scupper hole, insuring access to water, but not out the bottom!  If you are concerned with picking up weeds, stuff a piece of scotch bright or similar into the end as a filter.  Done for now.  I don't use clamps or glue, and it has worked great, but feel free...

PS.  in the picture the hose bib adapter is already pushed onto the piece of hose, and the check valve is on the left.  I  couldn't get the bib and the hose apart without really tweaking it.

Decide if you want to have an exhaust hose or not.  Having one makes the tank quieter, and allows you to direct the flow of water to a specific place if you care.  Most people don't, and just drill some 1/4" holes at the level they want the tank to drain at.  This works great, is fool-proof and can't go wrong.  I recommend it.

If that is your plan skip the next step.

 Still here?  I wanted to have a silent tank with a "proper" drain directly to a scupper hole.  If you decide to build the exhaust drain, look at the picture, see how long both pieces will need to be and if you will need to modify/cut a hole in the crate your tank sits in, if any to make it work.  Then simply push the pieces together.  A perfect fit, no glue no nada.

To make a screen to keep the bait from going down the drain I pushed two #2 treble hooks into the hose and bent the points out to dig in and make a six-way wire mesh.  If you only fish Macks and big sardines one treble hook works fine.  Smaller anchovies will get stuck in the single hook screen, and clog it.



Let's start with the drain.  Use the 1/2" wood bit and moderate speed.  If you have never done this you could practice on the middle of the lid, since it gets cut off anyway.  Unless you want to use that piece to make a closable top...

Here's the drain hole near the bottom in the back with the plug on a tether.

If you are clever you will put the plug somewhere easily reached from the cockpit on the water, allowing you to drain the tank before paddling in, or attempting a surf landing.

So now you did it, you ruined the bucket or tub, can't return it now!  Let's drill some more holes...

Just kidding, this was a test bucket for developing drilling techniques.


Now let's do the intake.  Figure out how deep you want the tank to fill and drill the intake hole slightly below that level, like 1/2" to an inch.  Or lower if it's more convenient.  Make sure you set the tank in the yak just like you will be using it and make sure that the intake is high enough above the bottom of the tank well, or better yet above a scupper hole, to accommodate the length of the threaded intake with the check valve installed.  Try to avoid extra hose, I'm not sure just how much "draw" you can get from these pumps, you might end up in trouble if you have gobs of extra hose on the end.  Drill through the side with the 1" bit.  Notice the 3/4" heater hose is a *perfect* press-fit, doesn't leak a drop!  So simple, so sturdy.  Check to see if you need to cut a hole in the crate or whatever you use to hold the tank, and make the piece of 3/4" the proper length to extend about an inch and a half into the tank.


Now press the 3/4" PCV valve elbow thingy you bought at the auto parts store for $2.99 onto the end of the hose, that's your infinitely adjustable spray nozzle.  I like a 45* angle to the right for gentle swirling action.  Shown in the picture is the proper procedure for priming the pump.  It needs to be done once at the beginning of the days fishing, or whenever you first get bait and want to turn the pump on.  Try and be able to do it from the seat.  Once you do this the pump can be turned on and will stay primed if you shut it off again.  Don't try to prime it while it's running.

Oh, after it starts pumping water twist it to whatever angle you like, as I said down at a 45* to the right is good.


Decided to do the exhaust hose?

Drill the 1 5/16" hole a little above the inlet elbow, so the inlet will be under water, and therefore quiet.  If you use a 1 3/8 bit the hole will be a little sloppy, wrap the hose with tape, glue it or don't sweat the minor leakage.  I ground down the sides of a 1 3/8 bit until it was 1 5/16, cuz I'm cheap and have a garage full of equipment, YMMV.

If you are using six volts, this exhaust is the perfect size.  If you are using 12 volts then the water level will rise slightly above the level of the hole before getting enough head-pressure to match the intake volume.  Running the pump on reverse polarity should help.  Or drill 1/4 inch holes along the waterline.  Or drill one big hole and use stainless wire to weave a screen.  Melt holes in the tank by heating the end of the wire and poking it through.  Or make a little intake cover out of a tiny plastic container with a bunch of holes, and bolt/tie-wrap or glue it to the inside.

Prototype, 1/3/8" hole stainless wire, worked great, but noisy.

Cut out the center of the lid, as the bait tends to try and jump up the sides.

You can pull apart the stuff and toss it inside with the battery to transport.

That's it!  It takes way longer to explain it all with pictures than it took to build.

However the REAL work was figuring it out, and then refiguring it until I had the simplest possible setup.

A couple of hints...

You can determine the proper flow rate needed for a bait tank by this formula: Volume in gallons divided by 0.06(constant) equals desired flow rate in gallons per hour.  A very common size that works well is three gallons, so 3/.06=50 gallons/hour.  The lowest commonly available flow rate in an aerator pump is 360 g/h, so a good idea is to run the tank on six volts.  A Six volt battery that costs $5.99 will run the tank over 12 hours before dropping below 40 g/h, a very easy, cheap and simple power source.  Three four-hour trips for six bucks is CHEAP.

Also the pump is sooo quiet on six volts that with the exhaust hose in place I have to physically feel the pump to see if it's running.  That is important to me, I like silent Yakking.

If you do run the pump on 12 volts, hook it up backwards.  This is suggested by the manufacturer of some pumps where less flow is desirable.  I measured 180 g/h with my 360 g/h pump reversed on 12 volts, still way too much, but better.  If you run full bore you will find that the exhaust hose pulls a siphon and makes sucking noises, drill a 1/8" hole in the top of the elbow to act as a siphon break, if you care.  I have also read that delicate bait like anchovies don't appreciate a flow rate designed for 40 gallons in a three gallon tank, but others have no trouble.

Currently I am using a PWM speed-control and a 12volt 7aH sealed gel-cel battery, commonly available at hobby stores like "Hobby People" for about $20, add $10 for a charger if you don't have one.  The PWM allows you to choose any flow rate from 0 to whatever the pump is good for.  I have found that 100 gph is a good all-around compromise and lasts for nearly 20 hours while also powering my Fish Finder.


Here is one of the mock-ups I used for testing, with the pump drawing from the same height as installed on the Fish N Dive.  I ran many such experiments with various combinations of batteries and speed-controllers etc. to arrive at the data presented above.

This is a kit from which you can build yourself an ideal speed controller for any bait tank.  It is Kit number 67, available for $14.95 plus $5 shipping from http://www.kitsrus.com

Tank installed in my Fish and Dive.


That's all for now, if I think of more I will post it.

Quietman AKA  Professor J Roe




....and in the true tradition of the Macgyver in us all, modified to suit the builders...


Here is JoeFish's tank, the first one someone else has built!

This is JoeFish's Tank, also in a fish N dive.  He used threaded fittings on the intake and found a cheap sprinkler system anti-siphon valve that only cost $4.99 instead of the $14.99 that west Marine charges for a marine valve.  He also decided to go ahead and run the pump on 12 volts, and reversed the polarity as shown in the picture.  The pump is the $15.99 bait aerator pump by attwood available at Wal-Mart.  JoeFish says that it is putting out 60 gph,. perfect!  Joe also added a switch and made a drilled piece of pvc into a nozzle instead of the press-on elbow I used. "Tricking" out the design with extras is a lot of fun for many builders.  Way to go JoeFish! 


This is SwampRat's installation on his Tarpon.  I like the way he fit the inlet/outlet diagonally, slick.  He also found clear 1"  ID hose to use for the outlet, looks nice.  I'd say great job!  Simple, clean, compact.




To all other tank builders out there, when you are done email me a picture or two and a description of any special modifications and how they work and I'll post it here to help others!






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