Periodic Leak. Help!

[mdk16]

I know this is a long shot without actually examining my system but I thought I would post this in the event that somebody can help.
Once every two months or so I wake up and have 1" of water in my stand. I'm thankful that it's an acrylic stand that is sealed otherwise I'm sure I'd be divorced by now.
I have a closed loop system running from the tank to a wetdry and returning back to the tank. On the return line I have a one way valve to prevent overflow during a power outage. I believe that if any part of this system was at fault, it would leak all the time, not perodically.
I also have a recirculating Octopus skimmer that is outside the sump, and runs from a line that is drilled from the wet dry, runs to the recirculating pump and then the return from the skimmer drops the water back into the sump to be returned to the display tank.
After these floods occur, I clean up the water, refil the loss water and everything runs great for weeks on end. Its not overflowing from the collection cup as I run that relatively dry.
I had a uv light on a loop that I recently removed because I thought that was the culprit.
Can water be escaping from the tube with the silencer on it coming from the skimmer? I don't see any evidence of a leak trail from anywhere. Any suggestions are greatly appreciated.
Thanks

 

[flower]

I am sure you have a very slow leak from somewhere, it takes it that long to pool into a noticeable leak.
There should be a salt creep trail. So clean salt off of everything, and wait to see where the buildup is.

 

[beaslbob]

I presume you have tested power out and power return with no problems.
One thing I forgot to check on my system is overflow failure/blockage. So simulate an overflow failure and check to see the sump pump runs out of water before the display floods. Then resume normal operation and mark the running sump height. Then never never add water to the running system that results in a sump level above that line.
my .02

 

[ryant]

Originally Posted by Flower
http:///forum/post/3217956

I am sure you have a very slow leak from somewhere, it takes it that long to pool into a noticeable leak.
There should be a salt creep trail. So clean salt off of everything, and wait to see where the buildup is.
I had that happen to me, salt creep was dripping making it look like a leak

 

[mdk16]

Thanks for the help so far, I don't believe it to be a slow leak because as of Monday night when I did a water change the stand was completely dry. One day later I have over 1" of water.
I'm interested in the overflow failing theory but not sure I understand it completely. I have a center overflow with three sides. How can I replicate a failure and how would this occur by accident?
Is it possible that water is escaping from the air line exiting the recirculating pump of the Octopus skimmer? This is very bizare.
Thanks

 

[gmann1139]

Is anything on a timer besides your lights? Double-check, it could be that something is powering off and overflowing.
This may sound stupid, but could it be not tank-related? It is that time of year when leaks spring up in roofs and walls.

 

[ifirefight]

[QUOTE=mdk16;3218118
Is it possible that water is escaping from the air line exiting the recirculating pump of the Octopus skimmer?
Yes. The "air line" will fill with water IF the pump to the skimmer is turned off. ..so the top of the airline needs to be positioned as high as the top of the skimmer to avoid water pumping out. If you have it lying on the ground, you will have a flood...Remember,this will ONLY happen when the pump is off,it will not happen when the pump is on because it is drawing air,preventing water from entering the breather tube.

 

[mdk16]

Thank you IFireFight. I think you may have solved this mystery. If so, I'm forever grateful.
Just to be clear, this is a recirculating skimmer so I have two pumps. One feeder pump from the sump and then the recirculating pump with the venturi needle wheel. The feeder pump exits from a drilled bulkhead on the side of the sump. Occasional, this pump slips off the fitting to the bulkhead (pressure fit only). When this happens the recirculating pump is still running. Is this when you believe the flood occurs?
The air hose is always up around the collection cup as it sits in a holder on the neck of the skimmer. I had actually added a 2nd piece of airline hose going from the silencer on top of the hose exiting the recirulating pump back to the sump in the event that the hose filled up with water. Now that I'm thinking about it the water would leak out of the fitting at the recirculating pump and never reach that 2nd tube. I will take off this modification.
If the feeder pump is causing these floods, then the easy fix is to secure this pump fitting to the bulkhead permenantly.
Thank you again,