Eshopps PF-1000 hob overflow - standpipe height?

[Dr4gula.f32]

I got one of these hob overflows used, but pretty much new for cheap. It seems the previous owner was tinkering with the standpipes. First, they are about 3mm from making a tight sealed fit, it's very strange. They have another piece of smaller acrylic tube glued inside the standpipe as some sort of vent, and it came with some maggie mufflers. I am going to make some proper fitting standpipes so they seal in the bulkhead fitting, but I am unsure how tall they are out of the box. All the photos I found online show them with a filter tube over the standpipe so I can't guess the height.

 

[exnisstech]

The pipe just sits loosely in the bulk head. It's not at all tight. The clear tube is to draw air and help reduce noise. I used a piece if airline and inserted it then move it up and down to find the sweet spot to make the overflow as quite as possible though I never got my pf800s to be silent. Are you aware you have to suck the air out of the u tube to get the syphon started? Just checking .
PS I no longer have mine but you can experiment with the height just start long and work your way down.