It's now official (couldn't really count the one on my QT).
System was built with dual 2" Dursos as when set up never heard of the Herbie. Though no issues with the display as the Dursos themselves where silent, just the noise for the water going over the sides of the overflow, what's been bugging me for years is the gurgling that I hear in a room that's used for the computer and as a bit of a library (the basement sump room and the 20' drain lines run directly below).
It's a somewhat modified Herbie since the display has the overflow chambers at each end with one drain in each. Basically using one chamber is the main, the other the backup. Pretty much worked from the start with the only problem being since running the water higher in the display, the level in the pump section of the sump was lower so was drawing some air. Didn't really want to add more water as still wanted to have lots room for drain back. Ended up removing the last baffle to increase level (will reinstall once trim off about on 1"). Other thing I had to do was cut back the amount of drain line running into the 'fuge, as found when I turn the pump off, water was siphoning into the sump.
2" Spears gate valve
Main drain at about 1000gph
So water doesn't go stagnate in the backup chamber, there's a 1/4" hole in the side of the stand pipe
Retired after close to 5yrs of trouble free use
