Sorry no pics and it woudl be very hard to see because the herbie pipe is under water. But this is how I set mine up to be as silent as possible.
- 1" drain PVC with female threaded cap at the end and treaded strainer on top so that fis cannot go down the pipe into the sump. Best to use a gate valve (I have bal valve but trust me getting it tuned just right is tough. WIth agate valve it will be very easy adjustments.
- 3/4" Durso that is about 2 inches higher (above) than the herbie so that when the water level rises and the water starts to fall into the herbie style pipe adjust it so that the water raises above the herbie so that the watter is actually draining without slurping or letting in air thats when it becomes complely silent. I set up the fail safe as a durso because I found when I did another herbie the water woudl trickly down the 3/4" herbie pipe and you woudl hear it so thats why I went durso and capped the top. There was no need for air mixure as there isnt alot of water going into that pipe and with the cap on top of the durso and no hole opening it makes it completely silent. If something shoudl get plugged in the herbie the water will rise and go into the durso pipe and you'll know and you'll be able to then here the durso sucking the water down to try and keep up. I've tried this by closing the ball valve on the herbie to simulate it being obstructed and even if I wasnt home the durso can keep up and when you do get home you'll know by the sound it makes.
Hopefully that helps It makes sence in my mind but maybe as I'm typing it may not
so any questions just let me know.