water level getting higher

[kpatrick]

For the past 3 months eveything has been fine with my overflow and sump but I just noticed that my water level in my display tank has actually risen to were its almost overflowing. It used to come up to the lip on the top of the tank and just even with the glass support in the middle of the tank but now in the last 2 days it actually sits on the lip and goes over the glass. I cleaned the internal overflow boxes and dont see anything blocking the u-tubes or external boxes. I tried raising and lowering the inernal boxes but that doesnt seem to help either. I also shut off the pump in my sump but that didnt help. I dont like the water that close tp the top! any ideas??
Thanks

 

[golfish]

are there any bubbles in your U-tube? you might want to add a ballgate valve on the output side of your pump so you can tweek it down a bit.

 

[kpatrick]

I dont see any bubbles and it does seem to have good flow. I may just start a new syphon and see if it works. If I had bubbles wouldnt that let the water actually flow over and out of the tank instead of stopping at the very top?

 

[golfish]

Its been so long since I've used that kind of setup...I know I had that problem before I just don't recall the fix..If you don't have a ballgate valve on the pump output side I'd still add one. That's not your problem but it wont hurt to add it.

 

[dskidmore]

Can you post a pict of your overflow?
Is the drainpipe line clogged?
It sounds like a restriciton in the line, that requires a higher water level to push the water past it.

 

[kpatrick]

The drain line runs pretty much striaght down. I dont see anything in the U-tubes or top of the drain lines in the external overflow box. I guess I have a few hours before bed... time to take pull the u-tubes and give them a good cleaning and restart the syphon and see if that helps. In the past I did use nylon on the bottom of the drain tubes to help catch algea and debris but removed it a few weeks ago after I thought a fish got sucked into the drain pipe.

 

[dskidmore]

Suggested diagnosis technique:
1. Turn off pump.
2. Send a ball (ping pong or golf ball the right size? or marbles?) down the drain tube that's close to the same diameter as the tube.
3. See if the ball freely falls through or gets caught on something.
Is the water deep over the baffle in the back of the overflow? (There should be a baffle right before the drain bulkhead, the water should be lower on the bulkhead side.)