Krish
RF STAFF
I think the overflows are only rated for 600 gph per if I remember correctly so 1200 gph max. Is it noisy in the overflow itself or where the water enters the sump? If in the sump, let me know how you have the input in the sump setup or even a picture. I had bad bubbling/girgling sounds on my sump before and all it took was one small fitting to solve my issue. Let me know though.