Water is overflow box questions

[Fredrxn]

Sup guys I have the water box reef 130.4…is it normal for the overflow box to change water level. One day it’s dead silent.. then next week it will be loud….. I have to keep readjusting it..return pump is Simplicity dc 1600

 

[blaxsun]

Yes. I try to keep the water level in my overflow just at the edge of the emergency drain.