trouble with overflow u tubes

[fish man]

I just hooked up my overflow box to my 75 gallon tank. Got everything up and running but I cannot get my two u tubes to stop having a bubble in them. How do I fix that problem? I even stuck a hose up in the middle of the u tube and it works for a second then back to a big bubble. Thanks in advance
Fish man
Kentucky

 

[2quills]

It's possible that your dual U tube overflow might be a little big for your tank. Typically the most ones that are made for a 75G tank usually only have 1 tube. What type of overflow is it? How about your return pump...what size, how many GPH?

 

[fish man]

my return pump is a mag 5. Should I try only using one u tube, or a different pump? I hope not a different pump because that is the only one I have. I just set the tank up for the first time in many, many months.

 

[acrylic51]

I would try using a different pump....I'm from the very old school of U tubes and if your pump isn't big enough you'll get air bubbles and eventually 1 will shut down. Do they both start out fine? I would try pulling 1 of the tubes before swapping pumps....

 

[fish man]

I pulled one of the tubes and it worked. Thanks for your help! Do u think a mag five is ok for a 75 gallon tank

 

[acrylic51]

Hard to say.....To many variables to guess....depends on your plumbing size, head pressure, how many fittings/types of fittings used.....You don't want all your flow through your sump from your return pump anyways.....