I'm about to install an Eshopps Eclipse S Overflow and a 3/4" Return kit from Glass-Holes, on a rimless 30L. It should look something like this: A few things I want to make sure about before I drill... Placement of the Eclipse Overflow internal box, and drilling template - Should the top of the internal box and template be flush with the top rim of the tank? Or an inch below? I can't find any info or photos of this overflow installed on a rimless tank. The instructions do not specify. I've never had a rimless tank, or an overflow, and I'm unsure what the water level should be exactly. Placement for the Return/drilling template - Should this template also be flush with the top rim? Or should the return hole be level with the overflow hole? What would the most ideal location for the return be in my case?