Sump Noise (Hot Tub Noise)

[rocketlily]

Finished hooking up the drain on my new tank and I'm running a Quietone 4000 to test the lines. The Durso standpipe is very quiet. No air noise, no gurgling. The noise is coming from where the water comes into the sump and overflows to the next compartment. It sounds like the constant rushing of water.

Any ideas on how to quiet this down. Is it possible that my first compartment is not large enough to handle the flow and it is being forced into the second compartment? I will be adding another Quietone 4000 or replacing it with a larger pump, which will increase the water flow.