Underfilled sump - help needed

[fisheb]

I've got a 250 gallon setup where the sump has recently become underfilled, causing the pump to have insufficient water to return to the tank. Conversely, the water level on the tank end is higher than normal, so adding more water to replenish the sump could cause the tank to overlflow at the top. Basically, the water levels between the tank and sump have gotten out of balance. What could be causing this?

I've had this same setup for well over 10 years with no changes. I did try swapping out the pump and filter media but those changes had no effect. Any suggestions would be very much appreciated.

 

[Milingu]

Sounds like the pump is pumping more water than the amount that can flow back.
Could the connection between tank and sump be jammed? Or did the diameter reduce because of deposits in the tubing?

 

[duanes]

Sounds like there is something plugging up the return lines running from tank to sump.
If gph pumpage remains the same, maybe there's a clog
I've had many things clog up the lines, plant pieces, a dead fish, snails, eveen shrimp.

 

[fisheb]

Sounds like the pump is pumping more water than the amount that can flow back.
Could the connection between tank and sump be jammed? Or did the diameter reduce because of deposits in the tubing?

Thanks very much for the fast response! That's a possibility I suppose. Water is definetly flowing into the sump but maybe it's not at a high enough rate due to some sort of blockage or buildup. How would I go about testing or clearing that?

 

[duanes]

My sump is about 2 feet to the right of the main tank.

So there is at least 3 ft of room where things can easily get stuck, and sucked into the overflow ports.

I like to add unions inorder to make it easy to clean out debris

And make it part of regular maintanence to brush out spots near bends where stuff can gunk up

 

[duanes]

Here are the unions used to separate lengths of pvc lines, in case of a clog.
In this way it's easy to just unscrew a certain length of pipe at different intervals along its span.

 

[esoxlucius]

If you have a well balanced overflow/return one minute, and then suddenly the return seems to be pushing more water than what can flow back into the sump, either one of two things is happening.

1. Your pump has all of a sudden starting pushing more water, for example a variable speed pump has been mistakenly turned up a few notches and the return can't cope, or...

2. There is a blockage in your drain somewhere, which, as already mentioned, could be anything from plant matter, a bit of bogwood lodged somewhere, dead fish remains, snails, or just maybe over the years the build up of bio film within your tubes has reduced the internal diameter causing the imbalance.



You'll know yourself if the pump has been turned up or not, if indeed you even have a variable speed pump.

I'd put money on it that it's a blockage somewhere, which of course only you can check for. Time to start uncoupling pipes and tubing.

 

[fisheb]

Thanks a lot for the detailed explanation. Very helpful! I used a shop vac to suck the tubes leading into the sump. This seemed to help a bit. Next, I will try to find some long, flexible scrub wire brushes to do some additional cleaning. I'm hopeful that will do the trick.

 

[whitakerthomas8627@gmail.]

I've got a 250 gallon setup where the sump has recently become underfilled, causing the pump to have insufficient water to return to the tank. Conversely, the water level on the tank end is higher than normal, so adding more water to replenish the sump could cause the tank to overlflow at the top. Basically, the water levels between the tank and sump have gotten out of balance. What could be causing this?

I've had this same setup for well over 10 years with no changes. I did try swapping out the pump and filter media but those changes had no effect. Any suggestions would be very much appreciated.

Slow down the return pump and check the suction side. Might need more water.

 

[fishdance]

If you have a top elbow outside the tank drain hole, swap it out for a TEE as this let's trapped air out and makes cleaning very easy. Having a top elbow is one of the most common mistakes I see.

Air bubbles can reduce gravity flow drains by 50% and create more gurgle noise.