Loaches Online Forum

Could it be a pinhole in a line?
(probably a stupid question...)

Well, I sealed all the joints with electrical tape and it still leaks. I don't see how they could of leaked anyway because I used plenty of pvc cement and primer on the joints. The only thing I can think of is that the air must be coming in with the water, but when I turn off the pump and stop the water flow it still leaks.

Shari - maybe that's it. It's PVC pipe with 1/8" thick walls though.

It looks like I'll have to take it out and pressure test it, to find the leak.

Man chefkeith,

you are the master builder! I bow to the....

always cool to see your innovative projects. makes me want to build things...

Thanks for the info on your setup.

I hope that you can find the leak.

if it's PVC more likely a hairline crack somewhere? Stress any pipes while you were assembling?

Any way to pressurize the plumbing with either air or water? (especially air) Then you could find the leak because the water (if that is what you used) will leak out, or you can soap-test each joint to find an air leak. I say especially air, because the leak might be small enough to pass air but not water.

Thanks LoachOrgy. I enjoy building things, but I don't like fixing things though.

Keith- I hope so too. In the meantime, I’ll turn off all the pumps if I can’t keep a close eye on the tanks. I also have plenty of dry beach towels on the floor just in case.

Shari- I don't think clumsy me cracked anything. It's possible though. I thought maybe the leak was where the airline valve is screwed into the pipe. I took the valve off and put teflon tape on the male threads, but it still leaked. My only other thought is that the female threads on the pipe must be bad.
I made a video clip of the leak.
http://www.youtube.com/watch?v=A1x8HXIIZH8

Diana- Thanks’, that’s good advice. I might give the soap-test a try.

Another way to pressure test small things like this is with air pressure and a dunk tank. I use to do pressure tests after welding small fuel tanks or exhaust systems.
With this overflow, I can put caps on all the pipe ends, then connect an air pump to the airline valve, then dunk the pipes underwater in a bathtub. Air bubbles should appear in the water immediately where there is a leak.

Good video showing the leak. It confuses me a bit since if the water flow is off, but the venturi effect on your airline hose looks to be drawing both water and air, it must be getting the water from your tank. This means that the water level in your two overflow pipes in the aquarium must be dropping. Is it dropping low enough to get air, in which case there is no leak at all?

Maybe I have misunderstood something. This would not explain what is happening when the water is flowing unless it also lowers the water level in your two overflow tubes enough to cause some splashing and then some bubbles get through.

Can the air be coming up the pipe backwards from the water flow direction?Ya know ,from the sump. I have a break in my drain. A siphon box on the back of the tank so the only part air tight and full of water is the siphon tube over the back. It then goes in a box with a drain higher than the pipe coming from my tank to maintain a siphon over the back whether or not the pump runs.The siphon is maintained between the tank level and siphon box level. The tube between stays full of water .The drain from here lets water cascade over into a drain that is open to my sump. This re starts on its own and minimizes chances to get air into your siphon tube and causing a stoppage or slowing of flow.

And a dunk tank is not far away, either!

Just read through this thread for the first time. Looks like an awesome project, and hope you get the leak resolved. Overflowing tanks isnt fun! I'm setting up my first overflow/sump tank setup and its going in a carpeted family room so I gotta make sure she aint gonna flood lol. And you've inspired me to get my project finished... I'll have to start up a journal thread soon.

Keith- When the pump is off, there is still about 10" of water in the intake pipe, but after about 5 minutes the venturi will suck all the water in and break the siphon.

Tinman- there is a vent to prevent air from going back up.



I'm going to do the pressure test right now and end this problem once and for all.

I found the leak. It was in the lever on the airline valve. In this pressure test video you can see it leaking-
http://www.youtube.com/watch?v=LOrpoQ2rdA4

I removed the valve and put a patch over the hole on the pipe. It will take a few days for the silicone on the patch to dry.

I'm just going to put a check valve on the pipe to remove the air from the overflow, and then connect the check valve to some airline going to the venturi intake. Alot of people are using the check valves with success.

To bad my idea of putting a lever valve on the overflow didn't work.

Glad that you solved this problem.

I've seen the Tom Aqualifter pump often used to keep the overflows primed... ever look at those? There only like ten bucks if memory serves.