Any ideas?

[NoobieReefer]

Yesterday I upgraded my 20 gal sump to a 40 gal sump. I've tried just about everything but I cant figure out my problem. I have a overflow box for my non drilled tank. I have a 1 inch drain and a 750gph pump. Before I changed the sump it was working fine but now its making noise. Its making a gurggling noise. At first I thought it was the flex drain pipe that was causing it to make noise because of the odd bend it had. Then I did the drain with PVC and still the same problem. I even tried a 350 gph pump and it still making noise! I've tried just about every combination and i can't seem to get it to not make a gurggling sound! Any ideas?:irked:

 

[DevIouS]

How far down is your drain pipe in the sump (below water level) & is it angled or just straight down?

 

[18oreefer]

i sometimes get that noise when when the water is draining to the sump faster then it can be returned to the tank. if you dont already have a valve in your drain line put one in and close it down till you get the drain and return matched.