overflow help.. Utube bubble and drain noise

Just started my overflow.. its running but there is a massive bubble in the U tube now and bubbles coming out of my piping in the sump .
What should I do about the bubble? I have the box inside the tank as low as possible.
Also, the draining noise is pretty annoying. What can I do to get rid of it? The water is just flowing over the edges of the tube in the back of the overflow.
Thanks.

 

run a tube up the u- tube and suck the air out. If your flow rate is slow it will also not move water fast enough to purge small bubbles out. Overtime small bubbles will turn larger and break the syphon

EDIT: What i meant by "flow rate" is the rate of the return pump. Hope that helps. As for the noise we need more info on your set-up.

 

its a HOB overflow with a 1" U/J tube.
My return is 600gph. I was told that with a 1" tube, the return would be okay.

 

Any suggestions on what to do about the bubbles coming out of my piping in the sump? its a ton of bubbles...

 

Depending on the brand of the pump and the hieght from the sump to the return you may be getting as little as 250 gph or less thru the tank because of head loss. Other factors like return line diameter, number of 90* elbows, 45* elbows and valves will knock your head down even more.

CrazyA is spot on by saying the bubble in your tube is because there isn't enough flow through your tank. Even if you sucked most of it out when starting the siphon there should have been enough movement to push the remaining out.

A 1" Utube is plenty to get the water from skimmer box to overflow box. The problem is most likely not enough head pressure to provide sufficient flow.

 

+1 on the pump info.
Also if you are experiencing bubbles in the sump, put a filter sock on the output side of the down drain. This will keep most bubbles in check. Or do a search in here on bubble traps in the sump. Or try the filter pad technique which worked for me. I'll post a pic later on today, but mine is approx 13" x 10". It blocks all bubbles from making it to the return pump.