Overflow flow to sump fluctuations

[clancaster23]

My tank has been running with a sump for about two months now. All this time the U tube has worked fine until today. Today for some reason I got a decent sized air bubble toward the back of the tube on the outside going down inside the outer half of the box. Now the way the sump is set up, on the left is the fuge section, the middle is the return section and on the right is the skimmer section. I have pipes going to both ends of the sump. Ever since I set up the sump the left side, the fuge section is always the side that had the air coming out of it and this was creating some flow to move the chaeto around. I shut everything off and pulled the U tube out and resiphoned it. Now all the air is coming out in the skimmer side and I have just water flow in the fuge section and it's just a nice calm section and my cheato is just floating still in a corner. What I want to know is what determines what end the air comes out? How can I get more flow in the fuge side to get a little circulation on that end again or possibly getting the air on that side again like it was?

 

[RockStacker]

Do you have one overflow and the overflow pipe is split to go to the two ends of the sump?
Or do you have two separate overflow boxes/U-Tubes?

 

[clancaster23]

One overflow and U-tube. The drain comes out of the overflow as one pipe and I have a T under the stand just above the sump tank where it splits and goes to both ends of the sump.

 

[RockStacker]

One overflow and U-tube. The drain comes out of the overflow as one pipe and I have a T under the stand just above the sump tank where it splits and goes to both ends of the sump.

I suggest replacing the tee with a Y splitter and put ball valves on each of the two split lines. This way you can control how much water flows through each line.
Just make sure you DO NOT CLOSE BOTH valves.

 

[clancaster23]

I don't know if I can find a 1/2" Y pvc piece. Not even sure how I'd hook that up. I am considering the ball valves though.

 

[clancaster23]

Coincidentally I just had to once again get an air bubble out of the Utube again, plug the pump back in and now all the air is going into the fuge like I want. Drives me insane. Still will put in ball valves on each side though.

 

[RockStacker]

Coincidentally I just had to once again get an air bubble out of the Utube again, plug the pump back in and now all the air is going into the fuge like I want. Drives me insane. Still will put in ball valves on each side though.

Significant air pockets forming on the top of the U-tube usually indicates inadequate water flow through the overflow and through the tube.
With adequate flow, all those bubbles would have been dragged down and out the tube.

 

[clancaster23]

Yeah, I think I just did a crappy job last time I did it. There was a nickel sized bubble from the start last time but I didn't have the time to do it over again. It looks fine now, all bubbles are just flowing right through. This is why when I do my upgrade here soon, I'm definitely going drilled.