Overflow/drain pipe help!!

i upgraded to the Eshopps PF-1000 and the gurgling is gone. i reused my 1" u-pipe, the 1 1/4" that came with the 1000 let too much water out causing the water level to drop in the internal skimmer resulting in a lot of bubbles. my fear was getting a bubble buildup in the u-pipe.

The 1" u-pipe handles all the water my mag 9.5 can pump. it was the dual 1 1/4" return lines that did the trick. I have two pvc plumbed, 1 1/4" lines going to my refuge. it is probably overkill but the gurgling is gone so i am happy.

 

try lowering the overflow box in the dt if possible and maks sure the prefilter sponge is clean.