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Live Well mounted DIY Tuna Tube - final

Printed From: The Fishing Website
Category: General Forums
Forum Name: The Boat Shed
Forum Description: Discuss all things boating.
URL: https://www.fishing.net.nz/forum/forum_posts.asp?TID=108864
Printed Date: 21 Jun 2026 at 11:44pm


Topic: Live Well mounted DIY Tuna Tube - final
Posted By: Joker
Subject: Live Well mounted DIY Tuna Tube - final
Date Posted: 28 Apr 2015 at 7:01pm
I've done a bit of playing around working out how to fit a removable tuna tube on the boat that has a passive live well (FC boat) that can use the well to feed a tuna tube. I've got the pick up to replenish the well whilst underway and now getting a self contained system to put into the tank and recirculate the water.
Here is what I've come up with.
 
200mm Stormwater pipe (free)
 
big funnel $4 from the Clearance Warehouse off Lincoln Rd Auckland cut down to size to fit tight. Standard 28mm bilge pump pipe $2 per foot at Burnsco
 
Use the inner most marks on the funnel plus another for a good fit.
 
 
Note: no 90 degree bends giving maximum flow from 1100 gph bilge pump $28 from Silverdale Marine
 
2" collar cut from pipe and a slice cut out of the ring to fit inside tube. Pop rivet in - this is to hold the funnel and seal with a generous amount of silicon around the collar. Pull the funnel into the silicon tightly and leave to set. Back fill behind to get a good bond.
 
 
A 40mm bend outlet and another as an exhaust away from the bilge pump inlet to stop bubbles.
 
The bilge pump on its side works well and is pumping clear water and all is underwater preventing overheating. The 90degree bend vents aerated water away from the pump inlet.
 
 
The working trial off a battery charger. 28mm inlet and a 40mm outlet is perfect and stays at this level all of the time. No bubbles which I am to believe is a big no no and kills the bait.
 
 
Outlet in action running in only 3" water really aerating the live well too.
 
 
 
This is the pick up arrangement for replenishing the live well - all from the irrigation dept at Bunnings
19mm 90 degree bends pointing forward. The mount is a bait board offcut silicon glued to the tramsom.
 
 
The on/off/regulator switch on the inside
 
 
 
 



Replies:
Posted By: krow
Date Posted: 28 Apr 2015 at 7:25pm
Like the idea and it looks tidy too. 
How big (litres) is the pod in the back? I assume you can/do bung it so it fills up completely. Just a little concerned about making it heavy in the bum. I see you already carry an Auxiliary too. 


Posted By: Joker
Date Posted: 28 Apr 2015 at 7:32pm
I suppose the inboard mounted tank (a standard feature on FC boats) would be around 60 litres and fills up with the internal bung removed. The bung is a big one maybe 40mm and fills up passively and vents when up on the plane which was my initial pick up initiative. Once this was solved then I thought to use this as a sump for the tubes and I must say exceeds my expectations.
I leave the bung open and the pickup replenishes what goes out, once the level goes up then gravity pressure forces more out keeping the level static.
 
Yes, you notice the weight once filled but not as much as a mate standing at the stern. The boat is relatively wide beamed for its size and well supported at the stern so I am not concerned about the weight.
 
The weight concerned might be the difference between a 2-stroke and a 4-stroke on the back.


Posted By: of2fsh
Date Posted: 28 Apr 2015 at 9:56pm
Steve the tuna tube will need 1300 to1400 gallons per hour, I've got 1100 GPH and it keeps a skippie alive for just under 1 hour then it dies, bloody frustrating as I was hoping 1 tube would be sweet with 1100 as the next step in pump price is quite big.
I've tried a venturie system using 30 mm pipe under the hull and at 7 knots was no better.
Not shure what I'm going to do next season with the tube as I'm not 100% happy with it to be honest.
My pipe set up is identical to yours with funnel etc.

Pick up looks mint, good idea, wrap a bit of mesh around the pump pick up as fish scales get inside and block the impellor, kahawai scales seem to get into it even when you haven't caught a kahawai

-------------
2009 and 2010 BERKLEY SOFTBAIT COMP CHAMPS,Runner up 2013 ( solo),winner 2013/14 longest kingfish nz fishing competition


Posted By: Joker
Date Posted: 28 Apr 2015 at 10:12pm
Hi Wayne,
 
I have heard that it is critical to not get any bubbles at all within the stream from the pump to the tube other wise they will die. If you are picking up from under the hull into the bilge pump you may get some air or turbulence forced in.
 
I'm trying to use the livewell as a sump and recirculate as an option. I deliberately put no 90degree fittings nor shut off valves that will affect flow - so its direct 29mm pipe through 29mm funnel with only a gentle bend in the pipe. Research says that a 90 degree bend in the system can reduce the flow by as much as 40% and its volume rather than force needed.
 
I think venting the exhaust down and away from the pump made a really big difference rather than re-pumping turbulent water when I had it overflowing directly from the top bend before I put the downspout. It used to surge when pumping and now its solid with the 40 outlet pipe full with water.
 
I played around with this one until I got zero bubbles so I will see what it does in real life. It pumps a heap of water.
 
Keep you posted with what I find.
 


Posted By: of2fsh
Date Posted: 28 Apr 2015 at 10:42pm
Yes bubbles were a problem with my 1 st pick up, killed skippies in less than 10 minutes, good point re 90deg restricting flow, I've now lowered pump down under water line and force water into it with the under hull pickup, changed to a sealed specialist pump that has 32mm pipe inlet and 32mm outlet , real pain in the ass to be honest, skippies are bloody temperamental creatures.
Pick up placement is spot on, half way between side and keel strip opposite side from transducer .
Good idea piping outlet water away from pickup, another thing I underestimated was tube length, was bloody annoying having a big kahawai splashing water everywhere with its tail.
Be good to get out west this Sunday if your keen , give the tube a test before next season, still skippies around and maybe even a marlin

-------------
2009 and 2010 BERKLEY SOFTBAIT COMP CHAMPS,Runner up 2013 ( solo),winner 2013/14 longest kingfish nz fishing competition


Posted By: Kevin.S
Date Posted: 28 Apr 2015 at 10:51pm
Why can't you mount the bilge pump in the bottom of the tube, with its outlet directed straight into the funnel, so there would be no bend at all?  Just thinking out loud so there could be a very good reason not to do this.  I think smooth pipe may give a better flow than that crinkly stuff as well.  Looking pretty good so far though, hope it keeps them alive.


Posted By: of2fsh
Date Posted: 28 Apr 2015 at 10:57pm
Originally posted by Kevin.S Kevin.S wrote:


Why can't you mount the bilge pump in the bottom of the tube, with its outlet directed straight into the funnel, so there would be no bend at all?  Just thinking out loud so there could be a very good reason not to do this.  I think smooth pipe may give a better flow than that crinkly stuff as well.  Looking pretty good so far though, hope it keeps them alive.


Good point re smooth hose, generally guys are using 2800GPH pumps and running 2 tubes.these are $350 approx for the pump and a relatively large pump.
Bit hard to justify with 1 tube

-------------
2009 and 2010 BERKLEY SOFTBAIT COMP CHAMPS,Runner up 2013 ( solo),winner 2013/14 longest kingfish nz fishing competition


Posted By: Joker
Date Posted: 29 Apr 2015 at 9:05am
Originally posted by Kevin.S Kevin.S wrote:

Why can't you mount the bilge pump in the bottom of the tube, with its outlet directed straight into the funnel, so there would be no bend at all?  Just thinking out loud so there could be a very good reason not to do this.  I think smooth pipe may give a better flow than that crinkly stuff as well.  Looking pretty good so far though, hope it keeps them alive.
 
Good idea Kevin and now that I am running it on its side I can do it plus it will be inside the pipe and not take up extra space in the tank.


Posted By: Joker
Date Posted: 29 Apr 2015 at 6:34pm
I took Kevin's advice and mounted the pump inside the tube on its side pointing straight up. A spare piece of smooth 32mm PVC pipe pointing straight up with no bends or corrugation. 
4 32mm holes around the bottom to prime the pump seems to be ok. I made these away from the suction end of the pump, again to avoid turbulence and bubbles. 
 
I reckon its taking 20% less time to fill up so it must equate to increased flow. The exhaust works great and its impossible to overflow even with the hose pipe in the tube as well and seems to aerate the livie tank well.
 
 
 
Now to use the magic glue and make permanent. I might put another clamp at the top of the exhaust to protect it from the crew (son) - its only silicon glued in. You wouldn't believe just what he can break in a silly misuse kind of way. 


Posted By: :Hunter:
Date Posted: 29 Apr 2015 at 7:09pm
Ive got an 1100 for my tube and I can keep a Skippy alive all day, I only use 150mm pipe though which I think helps

Originally posted by of2fsh of2fsh wrote:

Steve the tuna tube will need 1300 to1400 gallons per hour, I've got 1100 GPH and it keeps a skippie alive for just under 1 hour then it dies, bloody frustrating as I was hoping 1 tube would be sweet with 1100 as the next step in pump price is quite big.
I've tried a venturie system using 30 mm pipe under the hull and at 7 knots was no better.
Not shure what I'm going to do next season with the tube as I'm not 100% happy with it to be honest.
My pipe set up is identical to yours with funnel etc.

Pick up looks mint, good idea, wrap a bit of mesh around the pump pick up as fish scales get inside and block the impellor, kahawai scales seem to get into it even when you haven't caught a kahawai


Posted By: of2fsh
Date Posted: 29 Apr 2015 at 8:07pm
Originally posted by :Hunter: :Hunter: wrote:

Ive got an 1100 for my tube and I can keep a Skippy alive all day, I only use 150mm pipe though which I think helps

Originally posted by of2fsh of2fsh wrote:

Steve the tuna tube will need 1300 to1400 gallons per hour, I've got 1100 GPH and it keeps a skippie alive for just under 1 hour then it dies, bloody frustrating as I was hoping 1 tube would be sweet with 1100 as the next step in pump price is quite big.
I've tried a venturie system using 30 mm pipe under the hull and at 7 knots was no better.
Not shure what I'm going to do next season with the tube as I'm not 100% happy with it to be honest.
My pipe set up is identical to yours with funnel etc.

Pick up looks mint, good idea, wrap a bit of mesh around the pump pick up as fish scales get inside and block the impellor, kahawai scales seem to get into it even when you haven't caught a kahawai


Yes it would help immensely , more flow past the fish, thanks for that idea I'll grab some 150mm from work and have a play

-------------
2009 and 2010 BERKLEY SOFTBAIT COMP CHAMPS,Runner up 2013 ( solo),winner 2013/14 longest kingfish nz fishing competition


Posted By: mozz
Date Posted: 30 Apr 2015 at 4:36am
Looks good Joker but I would be putting stainless hose clamps on everyone of those fittings. 1100gph may be a little low


Posted By: gap74
Date Posted: 30 Apr 2015 at 10:39pm
Your a genius! Just given me ideas to solve my tube problems! Thanks


Posted By: Joker
Date Posted: 01 May 2015 at 9:38am
Originally posted by gap74 gap74 wrote:

Your a genius! Just given me ideas to solve my tube problems! Thanks
 
Just for the record and for sharing with others what problems were you encountering?



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