HOB Overflow Question

Plumbed and wet tested my tank today with (thankfully) no failures. My only concern was the overflow noise. At first it had annoying levels of noise from both the in tank box (loud trickle) and the bulkhead box (gurgling). After running for a bit, the bulkhead side gurgling died down to an acceptable level but the in tank trickle remained loud. The water level in that box is approximatley 2" below the teeth...is this normal? According to RC head flow calculator, I am right where I wanted to be for overflow/return flow. Tank and sump return chamber levels have stayed stable.



Eshopps PF-300 overflow (300gph) w/ultraflex pvc 1"

Mag 3 return pump w/ultraflex pvc 3/4" to standard hob plastic outlet and 3' 4" head.