Sump Overflow Issue

Tham121988 · Mar 20, 2017

Hello,

I'm having an issue with my sump overflow box. It will work perfectly for some time, and then all of a sudden I will come back and the water in the sump tank is low and the tank water is almost overflowing. It's gotten worse. Water flows through fine though so I'm not sure what the issue is. I'll list my overflow and return pump below. Any advice would be appreciated. It's on a 12 Gal. Nano.

Taam Rio Plus 1100 Aqua Pump and Powerhead - 382 GPH
Eshopps AEO10100 Overflow Nano Boxes for Aquarium Tanks

Thank you!

Rjramos · Mar 20, 2017

If I had to guess, I would say that you are having issues with your u-tube that goes from the black prefilter box inside the tank to the clear one on the outside. Sometimes the cascading water in the black prefilter box causes air bubbles to become trapped in the upper curved portion of the u-tube. The small bubbles accumulate and turn into a big bubble over time and thus cause a reduction in water flow thru the u-tube. This reduction will cause a back up in the tank and a low water level in the sump below. Is the u- tube clear, and can you see an air bubble inside in the upper curved portion? If there is, the solution is to place a rigid course sponge (usually black), cut to size to fit between the cascading water and the intake of the u-tube.[emoji4]

webbrage · Mar 20, 2017

Can you take a picture of how high or low your box is set to it could be as simple as raising your box on the overflow and what @Rjramos said with the sponge works great

Tham121988 · Mar 20, 2017

I'm not seeing any bubble accumulation at the top of the U tube at this time. It is completely filled with water. I do however seem to over time have to restart the siphon because that does occur every now and then. I have an old filter that has the black sponge material you talk about. I will try that. If that is not the case, what else could it be? I re-siphoned last night and it was clear and running well but still getting water buildup at the top.

As far as the water level that its set to... it is set to be a bout 1/2 an inch below the rim of the tank. It is a covered nano tank. I have it set as low as it can go. The water goes all the way to the lip of the lid and if I didn't have a top it would overflow. I had to cut off my return pump to get this figured out.

Tham121988 · Mar 20, 2017

I'll take a picture of the overflow when the light comes on here soon.

Water Dog · Mar 20, 2017

Many years ago, I ran a similar Amiracle overflow box (remember them?

). Early on, what I found was that the prefilter sponge would clog up quickly and cause the issues that you're currently experiencing. I ditched the prefilter sponge and replaced it with a Stockman standpipe. Never had that issue again. Here are the DIY instructions that I used back then...

https://www.dursostandpipes.com/index.php/popular-modifications/140-stockman

Tham121988 · Mar 20, 2017

Haha! That actually just might be it Water Dog. I have all the items needed in the garage, so I'm about to try to do that. I will report back.

Thank you!

Rjramos · Mar 20, 2017

Tham121988 said:
I'm not seeing any bubble accumulation at the top of the U tube at this time. It is completely filled with water. I do however seem to over time have to restart the siphon because that does occur every now and then. I have an old filter that has the black sponge material you talk about. I will try that. If that is not the case, what else could it be? I re-siphoned last night and it was clear and running well but still getting water buildup at the top.

As far as the water level that its set to... it is set to be a bout 1/2 an inch below the rim of the tank. It is a covered nano tank. I have it set as low as it can go. The water goes all the way to the lip of the lid and if I didn't have a top it would overflow. I had to cut off my return pump to get this figured out.

You should not have to re-siphon. The fact that you are, leads me to believe that air is going in the intake u tube on the black box side. The end of the tube should be submerged at all times, if it exposes to air only momentarily, it will break your siphon.

Water Dog · Mar 20, 2017

No worries! For a temporary fix, just rinse out your sponge for now and flow should go back to normal till it gunks up again. Or you could just remove the sponge altogether, but it will be loud though.

Also, as the DIY instructions say in step #3, it's better to cut the 1"x1" square drain than all the little holes for the drain. That's how I did it and it worked flawlessly.