Need help locating a leak!

mse077

Feeder Fish
Mar 3, 2012
4
0
1
Mukilteo, Wa
My 2000 gallon tank is leaking and I can't find where it's leaking from. It started leaking around 5 gallons an hour in the middle of the night. The tank is plywood and sealed with fiberglass then pond armor. I am looking for ideas on how to locate the leak without completely draining the tank, but it has to be safe for my fish. She is a 40 pound pacu and I don't really want to remove her from the tank unless it is absolutely the last result. I'm thinking some sort of colored liquid that could show me where the water is escaping from?
 

millerkid519

Aimara
MFK Member
Feb 16, 2015
2,251
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stratford ontario canada
Do you have a picture of the tank? My first thought would be to check all seems and bulkheads. If that not it then empty the tank and reseal it. How old is your tank?

Another thought is that silicone sticks to pond armour. You could silicone the area if you find the leaking area
 
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Homer Siped

Jack Dempsey
MFK Member
Aug 30, 2015
194
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I have had a couple leaks in my plywood tank. Mine is only sealed with fiberglass . I started by draining it down about 3/4 full, wiping down wet areas and using a hair dryer to help dry it out, and so on until leak stops that way I had a reference point as to where leak was in relation to height . Once I figured out what height water stopped leaking I slowly added water back up an inch at a time until I could pin point what level leak was exactly at . Then search and search, drained mine completely so I could get inside, flash light and several hours you should be able to find it. I tried leaving water inside but get light headed leaning over looking . One thing I can tell you that makes it a real PITFA is where the water is visible usually isn't where leak is as it gets behind the fiberglass and runs the grain of plywood. I've never used pond armor so I don't really know what you should look for. My tank had been running almost 8 months and started leaking, found a pinhole about the size of a . In the fiberglass
 
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mse077

Feeder Fish
Mar 3, 2012
4
0
1
Mukilteo, Wa
I have had a couple leaks in my plywood tank. Mine is only sealed with fiberglass . I started by draining it down about 3/4 full, wiping down wet areas and using a hair dryer to help dry it out, and so on until leak stops that way I had a reference point as to where leak was in relation to height . Once I figured out what height water stopped leaking I slowly added water back up an inch at a time until I could pin point what level leak was exactly at . Then search and search, drained mine completely so I could get inside, flash light and several hours you should be able to find it. I tried leaving water inside but get light headed leaning over looking . One thing I can tell you that makes it a real PITFA is where the water is visible usually isn't where leak is as it gets behind the fiberglass and runs the grain of plywood. I've never used pond armor so I don't really know what you should look for. My tank had been running almost 8 months and started leaking, found a pinhole about the size of a . In the fiberglass
That's what I'm thinking too. We lowered the water a foot and it seems to have stopped leaking or slowed greatly. Unfortunately the fish is over 40 pounds so emptying the tank is not really an option without risking harm to her.
 

mse077

Feeder Fish
Mar 3, 2012
4
0
1
Mukilteo, Wa
_DSC7668.JPG 29104035_1647263538701153_2219180194202124288_o.jpg
Do you have a picture of the tank? My first thought would be to check all seems and bulkheads. If that not it then empty the tank and reseal it. How old is your tank?

Another thought is that silicone sticks to pond armour. You could silicone the area if you find the leaking area
We are hoping to climb in and check the bulkheads inside soon. None of the plumbing on the outside is wet, the water is presenting under the tank and opposite the plumbing, but because it's wood I'm concerned that it could be leaking from elsewhere and just pooling on that side because the floor is slightly sloped with a drain in it. 29104035_1647263538701153_2219180194202124288_o.jpg View attachment 1304249 View attachment 1304249 View attachment 1304249 View attachment 1304249 I'm certainly glad I did that at least.View attachment 1304249
 
Last edited:

mse077

Feeder Fish
Mar 3, 2012
4
0
1
Mukilteo, Wa
We are hoping to climb in and check the bulkheads inside soon. None of the plumbing on the outside is wet, the water is presenting under the tank and opposite the plumbing, but because it's wood I'm concerned that it could be leaking from elsewhere and just pooling on that side because the floor is slightly sloped with a drain in it. View attachment 1304250 View attachment 1304249 View attachment 1304249 View attachment 1304249 View attachment 1304249 I'm certainly glad I did that at least.View attachment 1304249
Sorry, not sure why that picture posted so many times......
 

Homer Siped

Jack Dempsey
MFK Member
Aug 30, 2015
194
52
36
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View attachment 1304251 View attachment 1304250
We are hoping to climb in and check the bulkheads inside soon. None of the plumbing on the outside is wet, the water is presenting under the tank and opposite the plumbing, but because it's wood I'm concerned that it could be leaking from elsewhere and just pooling on that side because the floor is slightly sloped with a drain in it. View attachment 1304250 View attachment 1304249 View attachment 1304249 View attachment 1304249 View attachment 1304249 I'm certainly glad I did that at least.View attachment 1304249
That tank is awesome as well as the fish man I thought I was the only one that had a leak in my plywood tank . Hopefully it's high on the tank and not towards the bottom . Mine was dripping almost 2 feet from where it was actually leaking from, got behind fiberglass and followed grain to the corner so it seemed that it was leaking from the corner. It took me several days to figure it out and a lot of swearing . Would think the plywood would saturate at leak and be simple to find
 

esoxlucius

Alligator Gar
MFK Member
Dec 30, 2015
3,670
13,557
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That tank looks about 4 ft deep at a guess. That's a lot of pressure. If your leak is literally a pin hole sized hole, or smaller even, and it is at the bottom of the tank, then as you lower the water level you may find the leak will stop but only because the pressure would have decreased. You've already confirmed my theory by lowering your water level by a foot and observing that the leak "seems to have stopped leaking or slowed greatly". You could well be on a wild goose chase with this leak.

You may have to temporarily rehouse that beast, drain your tank fully, dry it out, and recoat with pond armor. An absolute pita. I wish you luck. Nice tank by the way.
 

VLDesign

Silver Tier VIP
MFK Member
Mar 20, 2007
1,846
11
1,843
IL
Very nice tank.. I agree with esox. When my 2500 gallon tank first leaked it would only start leaking once I got over 30" of water and the leak was actually a micro crack in the corner bottom seam of the tank that would only expand after the pressure got greater. Which at the 30" mark was my magic number.

My fix was to drain, dry, and reinforce all corners with 8" bands of fiberglass and epoxy. I didn't use pond armor after discovering how awesome Max ACR was (Get it on ebay). I used heavy top of the line fiberglass cloth in 8 inch bands in al of the corners, and 8" overlaps on seams of fabric, then coated with 2-3 coats of ACR epoxy. 1 Coat to lay the glass down then 2 more afterwards.

This did the trick and to this day my 2500 tank is still leak free (Or so I am told by the new owners).
 
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